| 4742041281 | Amino acids found in eukaryotes are | L-amino acids | | 0 |
| 4742043887 | Glycine is the only | achiral amino acid | | 1 |
| 4742047845 | Nonpolar amino acids | glycine, alanine, valine, leucine, isoleucine, methionine, proline | | 2 |
| 4742064005 | Aromatic amino acids | tryptophan, phenylalanine, tyrosine | | 3 |
| 4742069498 | Polar side chain (non-aromatic) amino acids | Serine, threonine, asparagine, glutamine, cysteine | | 4 |
| 4742070550 | Negatively charged side chain amino acids | Aspartic acid and glutamic acid | | 5 |
| 4742071787 | Positively charged side chain amino acids | Arginine, lysine, histidine (nitrogen on side chain is protonated at physiological pH) | | 6 |
| 4742086051 | pKa | pH at which half of the molecules of that species are deprotonated
- at pH less than the pKa, a majority of the species will be protonated | | 7 |
| 4742094374 | zwitterion | - species with a positive and negative charge on it, cancelling out
most amino acids at physiological pH
- have a positive charge (amino group in acidic form)
- and a negative charge (carboxyl group in basic form) | | 8 |
| 4742105815 | Isoelectric point | pH at which a particular molecule carries no net charge
- for AA with a neutral side group the pI is equal to the average of the two pKa values | | 9 |
| 4742140963 | Peptide bond formation | example of a condensation or dehyrdation reaction b/c water is formed
- C of one AA's COOH group forms a bond with N of another AA's NH3 group | | 10 |
| 4742144850 | Peptides are read from | the N-terminus to the C-terminus | | 11 |
| 4742156352 | Primary and secondary structure | Primary structure: linear arrangement of amino acids
Secondary structure: local structure of neighboring amino acids (B-sheets or alpha helices) - due to hydrogen bonding | | 12 |
| 4742161524 | proline is often not found | in the middle of alpha helices or beta sheets
- or if so it introduces a turn or kink | | 13 |
| 4742171020 | Tertiary structure | - folding of the protein due to hydrophobic interactions, hydrogen bonds, disulfide bonds, ionic, covalent bonds, van der waals forces | | 14 |
| 4742175702 | Quaternary structure | - how a polypeptide interacts with another polypeptide
- not found in all proteins
- immunoglobulins have 4 subunits | | 15 |
| 4742209577 | Conjugated proteins | proteins with covalently attached molecules
- the attached molecule is called a prosthetic group, and may be a metal ion, vitamin, lipid, carbohydrate, or nucleic acid | | 16 |
| 4742317174 | Cofactors vs coenzymes | - cofactors are inorganic molecules (mainly minerals)
- coenzymes are organic molecules mainly the water soluble vitamins (not A,D, E, and K)
- induce a conformational change in the enzyme that promotes its activity
- tightly bound cofactors/coenzymes necessary for enzyme function are termed prosthetic groups | | 17 |
| 4742351998 | Cooperativity and cooperative enzymes | - displays a sigmoidal curve (michaelis-Menten) because of the change in activity with substrate binding
Cooperative enzymes: have multiple subunits and multiple active sites
- subunits may exist in a Tense (T) state: low-affinity
- or a Relaxed (R) state: high affinity
- one subunit changing states can affect other subunits to do the same
- ex. hemoglobin | | 18 |
| 4742369457 | Cooperativity | refers to the interactions b/w subunits in a multisubunit enzyme or protein. The binding of substrate to one subunit induces a change in the other subunits from the T (tense) state to the R (relaxed) state, which encourages binding of substrate to the other subunits. In the reverse direction, the unbinding of substrate from one subunit induces a change from R to T in the remaining subunits, promoting unbinding of substrate from the remaining subunits | | 19 |
| 4742376402 | Enzyme activity does what with temperature | tends to double in activity for every 10 degree increase in temperature until it reaches its optimum temp | | 20 |
| 4742478493 | Collagen | - trihelical fiber
- makes up extracellular matrix of connective tissue
- important in providing strength and flexibility | | 21 |
| 4742480644 | Elastin | - another important part of extracellular matrix of connective tissues
- primary role = stretch and recoil | | 22 |
| 4742483868 | Keratins | - intermediate filament proteins found in epithelial cells
- contribute to the mechanical integrity of the cell
- primary protein of hair and nails | | 23 |
| 4742485018 | Actin | - makes up microfilaments and thin filaments in myofibrils
- most abundant protein in eukaryotes
- have a positive side and a negative side | | 24 |
| 4742486658 | Tubulin | - makes up microtubules
- provide structure, chromosome separation during mitosis, and intracellular transport with kinesin and dynein
- has polarity like actin (negative end near nucleus) | | 25 |
| 4742490171 | Myosin | - primary motor protein that interacts with actin
- thick filament in myofibril
- crucial for sarcomere contraction | | 26 |
| 4742492455 | Kinesin vs dynein | - motor proteins associated with microtubules
Kinesins: anterograde transport
Dynein: retrograde transport | | 27 |
| 4742499264 | Cell adhesion molecules | Cadherins: group of glycoproteins that mediate calcium-dependent cell adhesion
- two cells of the same or similar type adhered using calcium
Integrins: important for binding to and communication with ECM, cellular signalling (important for clot formation)
- once cell to proteins in the extracellular matrix
Selectins: bind to carbohydrate molecules that project from other cell surfaces
- one cell to carbohydrates, usually on the surface of other cells | | 28 |
| 4742517233 | 3 possibilities for a when antibodies bind antigens | 1) neutralization of pathogen or toxin
2) opsonization - marking for destruction
3) agglutination - creating insoluble antigen-antibody complex that can be phagocytized and digested | | 29 |
| 4742563176 | In electrophoresis anions move toward the ______ and cations move toward the _______ | cations move toward the cathode (negative charge)
and anions move toward the anode (positive charge) | | 30 |
| 4742565559 | SDS page
Isoelectric focusing | SDS page: separates protein on mass alone (SDS denatures proteins and covers them in negative charge)
Isoelectric focusing: separates proteins based on their isoelectric point using a gel with the pH spectrum and an electric field, a cathode (negative charge) at the basic end of the gel will bring positively charged proteins to their pI where they will become unprotonated
- opposite happens at the other end | | 31 |
| 4742603522 | Bradford protein assay | - Coomassie blue die is used to measure the concentration of protein
- dye changes colours as it gives up protons to the protein the different colour can be measured with a spectrophotometer and compared to a known curve of protein concentration | | 32 |
| 4742961020 | Enantiomers | nonsuperimposable mirror images of each other
- any molecule that contains a chiral carbon (4 different groups attached) and no internal planes of symmetry has an enantiomer
- a compound can have only one enantiomer | | 33 |
| 4742976241 | diastereomers vs epimers | Diastereomers: two sugars that are in the same family that are not identical and are not mirror images of each other
Epimers: a special type of diastereomers that differ in configuration at exactly one chiral center | | 34 |
| 4742996414 | Alpha or beta anomers | alpha anomer: -OH group of C-1 is trans to the -CH2OH
Beta anomer: -OH group of C-1 is cis to the -CH2OH | | 35 |
| 4743003056 | Anomeric carbon | the new chiral center formed in ring closure; it was the carbon containing the carbonyl in the straight-chain form | | 36 |
| 4743040087 | Sucrose, lactose, maltose | Sucrose: glucose and fructose
Lactose: galactose and glucose
Maltose: glucose and glucose | | 37 |
| 4743042706 | Cellulose, starches, glycogen | Cellulose: main structural component of plant cell walls and is the main source of fiber in the human diet, made up of beta-D-glucose molecules linked by beta-1,4 glycosidic bonds
Starches: main energy source for plants, glucose linked by alpha-1,6 glycosidic bonds (amylose - non branching) (amylopectin - branching)
Glycogen: main energy source in animals, highly branched | | 38 |
| 4744824759 | beta and alpha amylase | Beta amylase: cleaves amylose at the reducing end of the polymer to yield maltose
alpha amylase: cleaves randomly along the chain to yield shorter polysaccharide chains | | 39 |
| 4744826898 | glycogen phosphorylase | functions by cleaving glucose from the nonreducing end of the glycogen branch and phosphorylating it, thereby producing glucose 1-phosphate | | 40 |
| 4744797845 | Mutoration | interconversion b/w anomers of a compound | | 41 |
| 4744801560 | Tautomerization | a rearrangement of bonds
- ketose sugars undergo tautomerization to undergo keto-enol shifts, which forms an aldose, which then allows them to act as reducing sugars | | 42 |
| 4744803717 | Anomerization | refers to ring closure of a monosaccharide, creating an anomeric carbon (can than turn into a hemiacetal or hemiketal) | | 43 |
| 4744891463 | Fully saturated fatty acids | have only single bonds
- carbon is considered saturated when it is bound to four other atoms
- have greater van der waals forces and are more often to be a solid at room temperature | | 44 |
| 4744894494 | Unsaturated fatty acids | form one or more double bonds
- double bonds introduce kinks into the fatty acid chain, which makes it difficult for them to stack and solidify
- more often liquid room temp, ex. olive oil | | 45 |
| 4744918648 | Glycosphingolipids, cerebrosides vs globosides | Glycosphingolipids: sphingolipids with head groups composed of sugars bound by glycosidic linkages
Cerebrosides: have a single sugar
Globosides: have two or more | | 46 |
| 4744974538 | Terpenes | odiferous steroid precursors made from isoprene, a five-carbon molecule
- one terpene unit (monoterpene) contains two isoprene units | | 47 |
| 4744975901 | Steroids | contain three cyclohexane rings and one cyclopentane ring
- oxidation state and functional group may vary | | 48 |
| 4744977825 | Prostaglandins | autocrine and paracrine hormones that regulate cAMP levels. They have powerful effects on muscle contraction, body temperature, the sleep-wake cycle, and wain | | 49 |
| 4744986636 | Vitamin A (carotene) | is metabolized in retinal for vision and retinoic acid for gene expression in epithelial development | | 50 |
| 4744987569 | Vitamin D (cholecalciferol) | metabolized to calcitriol in the kidneys and regulates calcium and phosphorus homeostasis in the intestines (increasing calcium and phosphate absorption), promoting bone formation
- deficiency - rickets | | 51 |
| 4744990686 | Vitamin E (tocopherols) | act as biological antioxidants. Their aromatic rings destroy free radicals, preventing oxidative damage | | 52 |
| 4744992186 | Vitamine K (phylloquinone and menaquinones) | is important for formation of prothrombin a clotting factor. It performs posttranslational modifications on a number of proteins, creating calcium-binding sites | | 53 |
| 4745018165 | Saponification | is the ester hydrolysis of triacylglycerols using a strong base - making free fatty acids - aka soup
- usually use lye
- soaps act as surfactant (lower surface tension at the surface of a liquid) | | 54 |
| 4745077580 | More saturated fatty acids make for a ______ fluid solution | make for a less fluid solution | | 55 |
| 4745096279 | Nucleoside vs Nucleotide | Nucleoside: composed of five-carbon sugar (pentose) bound to a nitrogen base and are formed by covalently linking the base to C-1'
Nucleotides: formed when one or more phosphate groups are attached to C-5' of a nucleoside | | 56 |
| 4745105519 | DNA backbone | alternating sugar and phosphate
- always read 5' to 3'
- 3' end has free C-3' -OH group
5' end has C-5' phosphate group or -OH group | | 57 |
| 4745109954 | Pyrimidines | Cytosine, thymine, uracil (CUT the Pye) | | 58 |
| 4745111158 | Purines | Adenine, and guanine (PUre As Gold)
- two rings | | 59 |
| 4745497745 | Nuclesosome | two of H2A, H2B, H3A, H4A histones with 147 bp of DNA wrapped aroudn | | 60 |
| 4745507899 | Heterochromatin vs Euchromatin | Heterochromatin: condensed DNA, transcriptionally inactive
Euchromatin: uncondensed DNA, transcriptionally active | | 61 |
| 4745526516 | Helicase, DNA topoisomerase II (gyrase) | Helicase: unwinds DNA
Topoisomerase II: cuts DNA and relieves tension caused by twisting | | 62 |
| 4745531318 | DNA polymerases | read the DNA in the 3' to 5' direction and synthase the complimentary strand in the 5' to 3' direction | | 63 |
| 4747030925 | Monocistronic vs polycistronic | Monocistronic: in eukaryotes, each mRNA translates into only one protein
Polycistronic: in prokaryotes, each mRNA that can be translated into different proteins based on where translation begins | | 64 |
| 4747037543 | Amino acids attach to which end of a tRNA molecule | 3' hydroxyl end | | 65 |
| 4747040359 | start and stop codons | start: AUG - methionine
Stop: UAA, UAG, UGA | | 66 |
| 4747043485 | The genetic code is degenerate b/c | more than one codon can specify a single amino acid
ex. AAU, AAC both for Asparagine | | 67 |
| 4747045417 | Missense mutation | one AA substitutes for another
- nonsense mutation: a premature stop codon due to a mutation | | 68 |
| 4747076171 | RNA polymerase II reads in the | 3' to 5' direction, so that it forms RNA in the 5' to 3' direction during transcription | | 69 |
| 4747080167 | Post transcriptional hnRNA processing | 1) splicing: get rid of introns
2) 5' methyl-7-Guanylate cap
3) 3' Polyadenylation | | 70 |
| 4747087263 | Main promotor of trancription | TATA box: thymine, adenine rich sequenced bound by TATA binding protein
- ~ 25 BP upstream (-25) of transcription initiation site | | 71 |
| 4747088585 | RNA pol I, II, and III | RNA pol I: rRNA
RNA pol II: mRNA & snRNA
RNA pol III: tRNA (and 5S rRNA) | | 72 |
| 4747099734 | Eukaryote ribosomes vs prokaryote ribosomes | Eukaryotes: 80S, made up 60S (5S, 5.8S, 28S) & 40S (18S) subunits
Prokaryotes: 70S, made up of 50S (5S and 23 S) and 30S (16S) | | 73 |
| 4747106992 | Shine-Dalgarno sequence | prokaryotes translation initiation site | | 74 |
| 4747112250 | peptidyl transferase | enzyme in the large ribosomal subunit that facilitates the formation of a peptide bond, transferring the polypeptide in the E site onto the AA in the A site
- uses GTP | | 75 |
| 4747123872 | Operon (prokaryote gene regulation) | cluster of genes transcribed as a single mRNA
- very common in prokaryotes
- can be
- inducible (positive control):inducer removes repressor and transcription can proceed
- repressible (negative control): transcription proceeds until corepressor binds repressor then bind DNA preventing transcription | | 76 |
| 4747137471 | Operator | site where repressor can bind preventing transcription of Operon | | 77 |
| 4747177442 | Trp operon | when tryptophan is present in high concentrations it acts as a corepressor
- thus cell transcription of proteins used in creating tryptophan | | 78 |
| 4747179992 | lac operon | induced by the presence of lactose (when glucose is low) and induces genes for lactose metabolism | | 79 |
| 4747143161 | Transcription factors (eukaryote gene regulation) | have two domains: activation domain and DNA-binding domain
- bind DNA motif or response element and RNA pol to alter transcription | | 80 |
| 4747151918 | Acetylation | histone acetylases acetylate lysine residues making them less positive and decrease their affinity to histones, therefore opening up the DNA for transcription
- deacetylation = opposite | | 81 |
| 4747155424 | DNA methylation | silences gene activity via chromatin remodelling
- heterochromatin is much more methylated | | 82 |
| 4747194901 | Sense coding strand and antisense | sense coding strand is identical to the mRNA transcript
- antisense is the one transcribed | | 83 |
| 4747204962 | Peptide bonds are what kind of linkages | amide linkages | | 84 |
| 4747264752 | Cholesterol | increases cell membrane fluidity | | 85 |
| 4747267415 | Transmembrane proteins vs embedded proteins | transmembrane proteins actually traverse the membrane
embedded proteins are only associated with one side of the membrane | | 86 |
| 4747270784 | Gap junctions are made of | 6 connexin molecules which form a connexon
- a hydrophilic pore that connects adjacent cells | | 87 |
| 4747274768 | Desmosomes | bind adjacent cells by anchoring to their cytoskeletons
- interactions b/w intermediate filaments
Hemidesmosomes: attach cell to underlying membranes (ECM) | | 88 |
| 4747320345 | Colligative property | a physical property of solutions that is dependent on the concentration of dissolved particles, but not on the chemical identity of those dissolved particles
ex. osmosis, freezing point depression, boiling point elevation, and vapour pressure depression | | 89 |
| 4747330725 | Osmotic pressure | a sucking force, water will move toward the compartment with the greatest osmotic pressure | | 90 |
| 4747391552 | GLUT 2 | low-affinity glucose transporter found in hepatocytes and pancreatic cells
- captures excess glucose passing through portal vein from intestine after a meal
- in pancreas serves as an indicator for insulin release - if blood glucose concentrations are high, glucose will enter beta-islet cells and with glucokinase cause insulin release
- km ~ 15mM | | 91 |
| 4747399326 | GLUT 4 | in adipose and muscle
- insulin causes additional GLUT 4 movement to the membrane
- km ~5 mM (which is the normal glucose level in the blood) therefore when more glucose in blood, need more transporters to increase glucose intake | | 92 |
| 4747416449 | Red blood cells only method of acquiring energy | glycolysis b/c they lack mitochondria | | 93 |
| 4749565337 | Glycolysis takes place in | the cytoplasm | | 94 |
| 4749569312 | Rate limiting enzymes of
1) glycolysis:
2) fermentation:
3) glycogenesis:
4) glycogenolysis:
5) gluconeogenesis:
6) Pentose phosphate pathway: | 1) glycolysis: Phosphofructokinase-1
2) fermentation: lactate dehydrogenase
3) glycogenesis: glycogen synthase
4) glycogenolysis: glycogen phosphorylase
5) gluconeogenesis: fructose-1,6-bisphosphatase
6) Pentose phosphate pathway: glucose-6-phosphate deydrogenase | | 95 |
| 4749580386 | Hexokinase and Glucokinase | Hexokinase: present in all tissues, low km, inhibited by glucose-6-phosphate
Glucokinase: present in liver and pancreatic beta-islet cells, high km, induced by insulin in hepatocytes
- both use ATP and phosphorylate glucose to glucose-6-phosphate, which prevents it from leaving the cell | | 96 |
| 4749589928 | Phosphofructokinase 1 (PFK-1) | - rate limiting enzyme & main control point in glycolysis
- converts fructose-6-phosphate to 1,6-BP and uses ATP
- inhibited by: ATP, citrate, and glucagon (indirectly)
- activated by: AMP, F2,6-BP
PFK-2: activated by insulin, turns a small amount of F-6-P into F-2,6-BP which activated PFK-1
- inhibited by: glucagon - therefore inhibits PFK-1 | | 97 |
| 4749608501 | Substrate level phosphorylation | placing an inorganic phosphate (Pi) onto ADP to form ATP
- does not require oxygen | | 98 |
| 4749621615 | Irreversible enzymes of glycolysis | 1) glucokinase or hexokinase
2) PFK-1
3) pyruvate kinase | | 99 |
| 4749624598 | Adaption to high altitude (low pO2) involves | - increase respiration
- increased oxygen affinity for hemeglobin (initial)
- increased rate of glycolysis
- increased [2,3-BPG] in RBC (over 12-24 hour period)
- normalized oxygen affinity for hemeglobin restored by the increased levels of 2,3-BPG
- increased hemeglobin (over days to weeks) | | 100 |
| 4749700431 | Fructose metabolism | fructokinase converts to fructose-1-phosphate
- aldolase B converts to glyceraldehyde and DHAP
- both these are downstream from the rate limiting step of glycolysis (PFK-1), therefore high-fructose drinks supply a quick source of energy to both anaerobic and aerobic cells | | 101 |
| 4749736043 | Glucogenic amino acids | all except leucine and lysine | | 102 |
| 4749751076 | Insulin will _______ fructose 2,6-BP and _________ gluconeogenesis
Glucagon will _______ F2,6-BP and ________ gluconeogenesis | Insulin will increase F2,6-BP and inhibit gluconeogenesis
Glucagon will lower F2,6-BP and stimulate gluconeogenesis | | 103 |
| 4749755968 | Acetyl-CoA ______ pyruvate dehydrogenase and _______ pyruvate carboxylase | Acetyl-CoA inhibits pyruvate dehydrogenase ane stimulates pyruvate carboxylase
- shift from burning pyruvate in citric acid cycle to creating new glucose molecules for rest of body
- Acetyl-CoA is crucial to gluconeogenesis
- the Acetyl-CoA comes from fatty acid oxidation | | 104 |
| 4749758063 | Cori cycle | RBC's convert glucose to lactate
- lactate is delivered to the liver where it is turned into pyruvate then used for gluconeogenesis - which supplies glucose for the RBCs | | 105 |
| 4749765032 | Gluconeogenic specific enzymes and what they replace | pyruvate carboxylase - pyruvate kinase
Phosphoenolpyruvate carboxykinase - pyruvate kinase
Frucose-2,6-bisphosphatase - Phosphofructokinase 1
Glucose-6-phosphatase - glucokinase | | 106 |
| 4749784306 | Two major metabolic products of the pentose phosphate pathway | NADPH and ribose-5-phosphate | | 107 |
| 4753242861 | Glycolysis yields how many molecules of ATP per glucose | 2 ATP per glucose | | 108 |
| 4753253009 | Pyruvate is _________ transported into the mitochondria after glycolysis and is oxidized and decarboxylated by pyruvate dehydrogenase complex to from _______ | actively transported
to from Acetyl-CoA | | 109 |
| 4753258849 | Pyruvate dehydrogenase complexes 5 enzymes | 1) Pyruvate dehydrogenase: oxidizes pyruvate and yields CO2. Mg2+ required, TPP coenzyme
2) Dihydropropyl transacetylase: lipoic acid accepts 2 carbon molecule from TPP and oxidizes it to yield an Acetyl group, Acetyl-CoA is formed
3) dihydrolipoyl dehydrogenase: FAD used to reoxidize lipoic acid, FAD reduced to FADH2, NAD+ is reduced to NADHf
4) pyruvate dehydrogenase kinase
5) Dehydrogenase phosphatase | | 110 |
| 4753329874 | Citric Acid cycle rate limiting stem and enzyme | D-Isocitrate to alpha-ketoglutarate
- Isocitrate dehydrogenase | | 111 |
| 4753344350 | Synthase vs synthetase | Synthetases: use ATP in the reaction
Synthases: do not use ATP | | 112 |
| 4753354928 | Please, ah, can I keep selling sex for money, officer?
Mneumonic for TCA cyle | Pyruvate, acetyl-CoA, citrate, isocitrate, alpha-ketoglutarate, succinyl CoA, Succinate, fumarate, malate, oxaloacetate | | 113 |
| 4753385653 | Pyruvate dehydrogenase kinase and phosphatase | Pyruvate dehydrogenase kinase: phosphorylates PDH (pyruvate to Acetyl-CoA) if ATP levels are high, preventing Acetyl-CoA formation
Pyruvate dehydrogenase phosphatase: reactivates PDH in response to high ADP levels
- PDH also inhibited by high levels of Acetyl-CoA | | 114 |
| 4753428445 | glycolysis and fermentation occur | in the cytosol | | 115 |
| 4753473361 | in ETC
which complexes pump protons into intermembrane space?
Acquire electrons from NADH
Acquire electrons from FADH2
have the highest reduction potential | I, III, IV (all except II pump protons, IV is only 2 protons)
Complex I acquires electrons from NADH
Complex II acquires electrons from FADH2
Highest reduction pot = IV (must be last step) | | 116 |
| 4753511791 | Uncouplers | inhibit ATP synthesis without affecting the electron transport chain | | 117 |
| 4753522649 | Pancreatic enzymes responsible for digesting fats | pancreatic lipase, colipase, and cholesterol esterase
- broken down into cholesterol, 2-monoacylglycerol, free fatty acids,
- reform triacylglycerol and cholesteryl esters once absorbed into mucosa | | 118 |
| 4753540468 | Hormone sensitive lipase | - hydrolyzes triacylglycerols, yielding fatty acids and glycerol
- activated by decrease in insulin levels or increase in EP or cortisol levels
- active in adipose tissue | | 119 |
| 4753548501 | 1) Chylomicrons
2) VLDL
3) IDL (VLDL remnants)
4) LDL
5) HDL | 1) chylomicrons: transport dietary TAG and cholesterol from intestine to tissues
2) VLDL: transport TAG from liver to tissues
3) IDL: picks up cholesterol from HDL to become LDL, picked up by the liver
4) LDL: delivers cholesterol into cells
5) HDL: picks up cholesterol in blood vessels, delivers cholesterol to liver and steroidogenic tissues, transfers apolipoproteins to other lipoproteins (considered good cholesterol) | | 120 |
| 4753586091 | Alpha carbon | carbon 2 of a fatty acid | | 121 |
| 4753592884 | Palmitic acid | primary end product of fatty acid synthesis (16:0) | | 122 |
| 4753604963 | Rate limiting step of fatty acid biosynthesis | Acetyl CoA carboxylase | | 123 |
| 4753624137 | Rate limiting enzyme of fatty acid oxidation | Carnitine acyltransferase I: transport long-chain fatty acids (14 to 20 carbons) into the mitochondria | | 124 |
| 4753644329 | Alpha-lenolenic acid
lenoleic acid | alpha-lenolenic acid: 18:3 all-cis-9, 12, 15, an omega-3 fatty acid
Lenoleic acid: 18:2 cis,cis-9, 12, and omega-6 fatty acid
(omega is the last carbon, number refers to how many carbons the first double bond is away from the omega carbon) | | 125 |
| 4753651452 | excess acetyl-CoA from beta-oxidation of fatty acids is turned into | Ketone bodies: transportable forms of Acetyl-CoA, produced in the liver
- acetoacetate and 3-hydroxybutyrate | | 126 |
| 4753657738 | Acetyl-CoA cannot be used to produce | glucose via gluconeogenesis | | 127 |
| 4753659094 | Ketogenesis and ketolysis | Ketogenesis: favored by a prolonged fast and occurs in the liver, stimulated by increasing concentrations of acetyl-CoA
Ketolysis: favored during prolonged fasting, but is stimulated by low-energy state in muscle and brain tissue and does not occur in the liver | | 128 |
| 4753666092 | Glucogenic Amino acids | all but leucine and lysine
- can be turned into glucose via gluconeogenesis | | 129 |
| 4753666404 | Ketogenic amino acids | leucine, lysine, isoleucine, phenylalanine, threonine, tryptophan, and tyrosine
- can be converted to acetyl-CoA and ketone bodies | | 130 |
| 4753692568 | LCAT and CETP | LCAT: catalyzes the formation of cholesteryl esters for transport with HDL
CETP: catalyzes the transition of IDL to LDL by transferring cholesteryl esters from HDL | | 131 |
| 4753711872 | main gluconeogenesis precursors | lactate, glycerol (from TAGs), alanine, and glutamine (all glucogenic amino acids, aka not leucine and lysine) | | 132 |
| 4755579740 | Amino acids that are both glucogenic and ketogenic | PITTT
phenylalanine, Isoleucine, threonine, tyrosine, tryptophan | | 133 |
| 4755615110 | Gluconeogenesis occurs mainly in | the liver and kidneys | | 134 |
| 4755677658 | High energy electron carriers in cytoplasm | NADH (glycolysis, fermentation, TCA, ECT), FADH2, NADPH (PPP, lipid biosynthesis, bleach formation, oxidative stress, photosynthesis), ubiquinone (ECT), cytochromes (ECT), and glutathione (oxidative stress) | | 135 |
| 4755681917 | Flavoproteins | subclass of electron carriers that are derived from riboflavin (vitamin B2)
- also nucleic acid derivatives (FAD - flavin adenine dinucleotide or FMN flavin mononucleotide) | | 136 |
| 4755700510 | Postprandial state (well-fed state) | - greater anabolism than catabolism
- insulin is released with increased blood glucose levels
- promotes glycogen synthesis in liver and muscle
- liver converts excess glucose to fatty acids/ TAGs
- promotes TAG synthesis in adipocytes
- promotes protein synthesis in muscle | | 137 |
| 4755709699 | Two types of cells insensitive to insulin | nervous tissue and RBC's
- nervous tissue uses glucose from blood (why its concentration is maintained) unless in prolonged fasting state in which switches to ketones
- RBCs only use glucose anaerobically
but also kidney tubules, intestinal mucosa, β-cells of pancreas
- all these tissues need to take in glucose even when the concentration is low | | 138 |
| 4755713959 | "Fasting state"
Counterregulatory hormones (oppose insulin) | glucagon, EP, NE, cortisol, and growth hormone
liver: glycogenolysis, gluconeogenesis
Muscle and adipose: low insulin = release of amino acids and fatty acids (sent to liver for gluconeogenesis) | | 139 |
| 4755720442 | Prolonged fasting | further elevated EP and glucagon
- 24 hours - gluconeogenesis is primary energy source, glycogen stores are depleted
- rapid lipolysis = excess acetyl CoA = ketone bodies
- after several weeks the brain primarily uses (2/3rds) energy from ketone bodies | | 140 |
| 4755736560 | Insulin | peptide hormone secreted by β-cells of the pancreatic islets of Langerhans
- used for effective uptake of glucose in muscle and adipose tissue
- increases glycogen synthesis in liver by increasing activity of glucokinase and glycogen synthase (decrease activities of glycogen phosphorylase and glucose-6-phosphatase)
- increases amino acid uptake by muscle cells | | 141 |
| 4755748043 | Insulins affect on fat metabolism | Insulin increases:
- glucose and TAG uptake by adipocytes
- lipoprotein lipase activity - which clears VLDL and chylomicrons from the blood
- TAG synthesis in liver and adipocytes from acetyl-CoA
Insulin decreases:
- TAG breakdown in adipose tissue
- formation of ketone bodies in the liver | | 142 |
| 4755752871 | Glucagon | peptide hormone secreted by α-cells of the pancreatic islets of Langerhans, primary target is hepatocytes
- increased liver glycogenolysis (activates glycogen phosphorylase and inhibits glycogen synthase)
- increased liver gluconeogenesis (increases pyruvate carboxylase and PEPCK activity (pyruvate to PEP)
- increased liver ketogenesis and decreased lipogenesis
- increases lipolysis in liver (activates hormone sensitive lipase)
- glucagon is released due to low blood glucose, but also high amino acid concentration (arginine, lysine, histidine esp) | | 143 |
| 4755763212 | Glucagon increases | increases glycogenolysis, lipolysis, protein catabolism (gluconeogenesis), ureagenesis, ketogenesis, gluconeogenesis | | 144 |
| 4755770489 | Cortisol | glucocorticoid (steroid) released from adrenal cortex
- increases lipolysis and protein catabolism,
- inhibits glucose uptake in most tissues (muscle, lymph, adipose)
- increases hepatic output of glucose via gluconeogenesis, particularly from amino acids | | 145 |
| 4755776482 | Catecholamines | EP and NE, released from the adrenal medulla
- increase activity of liver and muscle glycogen phosphorylase = more glucose output by liver
- increase lipolysis via hormone-sensitive lipase | | 146 |
| 4755786971 | Thyroid hormones | activity is largely permissive (levels kept ~ constant)
Thyroxine (T4) - several hour latency period and can last for several days
Triiodothyronine (T3) - produces a more rapid increase in metabolic rate and shorter duration
- both increase O2 consumption and heat production (aka raise basal metabolic rate) | | 147 |
| 4755931185 | Ghrelin | hormone secreted by the stomach in response to signals of an impending meal (sight, sound, taste, smell)
- cause release of orexin | | 148 |
| 4755932073 | Orexin | - further increases appetite & involved in alertness & sleep-wake cycle | | 149 |
| 4755933637 | Leptin | secreted by fat cells to decrease appetite by suppressing orexin production | | 150 |
