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135 Cards in this Set
- Front
- Back
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Proteins are made of
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23 types of amino acids
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Proteins account for
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50% of the organic material in the body (17% total BW)
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Proteins provide
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4.32 calories per gram
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Proteins should be about
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12-15% of the daily caloric intake
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Carbohydrates should be about
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50% of the daily caloric intake (600 calories of simple CHO)
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To prevent significant protein breakdown
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100 grams of CHO are needed everyday
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Carbohydrates provide
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4.19 calories per gram
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The essential fatty acids are
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Linoleic, linolenic and arachidonic acid (provided by plants)
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Fats provide
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9.46 calories per gram
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8 original essential amino acids
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Lys, thr, met, val, isoleucine, tryptophan, leu, phenylalanine
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Thiamine deficiency leads to
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Beriberi – neurological disorder that leads to heart failure
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Ascorbic acid deficiency leads to
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Scurvy – rotting teeth and gums, spontaneous hemorrhage
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Riboflavin deficiency leads to
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Anemia, cracking of corners of mouth
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Folic acid deficiency leads to
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Anemia, weight loss and weakness
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Symptoms of vitamin A toxicity include
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Nystagmus, diplopia, ocular muscle palsies
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Kreb’s cycle takes place in the
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Inner compartment of the mitochondria – the matrix
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Nucleolus is the site of
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Ribosomal assembly
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RER is the site of
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Protein synthesis
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SER is the site of
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Lipid synthesis
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Microtubules are composed of
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Tubulin
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Microtubules provide a
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Supportive framework and a guide for organelle movement
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Microfilaments are made of
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Actin
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Microfilaments interact with
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Myosin
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Non polar amino acids are
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Glutamine and serine
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Polar amino acids are
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Asparagines and threonine
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Basic amino acids
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Histidine and threonine
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Acidic amino acids
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Aspartic acid and glutamic acid
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A peptide bond involves a linkage of
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CO-NH
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Globular proteins
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Tightly folded … water soluble…most enzymes are globular
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Fibrous proteins
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Water insoluble … serve a structural or protective function
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IgA
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Dimer…In secretions like saliva, sweat, tears, breast milk
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IgE
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Protects against parasites …hypersensitivity/ allergy rxns
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IgG
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Most abundant…crosses the placenta
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IgM
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Ist antibody to be produced…2-3 days after exposure
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Km, Michaelis constant
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Substrate concentration at which V = ½ Vmax
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Michaelis-menten equation
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V0 = (Vmax [S]) / (Km + [S])
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Competitive inhibitor
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Resembles the substrate…binds to the same site
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uncompetitive inhibitor
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Binds to the enzyme-substrate complex – not free enzyme
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Hemoglobin
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Two alpha and two beta subunits
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Oxygenation of hemoglobin
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Causes quaternary changes to the R state
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Deoxygenation of hemoglobin
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Causes iron to move into the heme plane – T state
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Structural changes of hemoglobin (R to T)
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Take place entirely across the alpha1-beta2 interface
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Lysozyme destroys the bond between
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NAM and NAG in the cell wall peptidoglycan
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Serine proteases include
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Trypsin and chymotrypsin
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Endergonic rxns
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Energy input required
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Exergonic rxns
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Energy produced
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G coupled rxns use energy from hydrolysis of
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ATP to GTP, for thermodynamically unfavorable reaction
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RED OX reactions
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Reducing agent (electron donor) oxidizing agent (acceptor)
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Henderson-Hasselbach reaction
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pH = pKa + log ([A-] / [HA])
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pH = - log [H+]
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pKa = - log (Ka)
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Acetyl CoA is the common product of
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Carbohydrate, fatty acid and amino acid catabolism
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Acetly carbons are oxidized
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To CO2 in the TCA cycle yielding NADH and FADH2
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NADH and FADH2 pass electrons to
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O2 producing H2O in oxidative phosphorylation
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Sucrose
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Glucose and fructose
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Lactose
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Glucose and galactose
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Maltose
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Glucose and glucose
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Glycosaminoglycans are polysaccharides…
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with one negatively charged carboxylate or sulfate group
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Examples of GAGs are
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Chondroitin sulfate, keratan sulfate, heparin
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Glycolysis
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10 rxns in the cytosol…produces pyruvate and 2 ATP
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In the presence of oxygen Pyruvate in converted to
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Acetyl CoA and enters the TCA cycle in the mitochondria
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Pentose monophosphate shunt
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In cytosol…Generates reducing power
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Products of the Pentose phosphate pathway
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12 NADPH and ribose 5-monophosphate(for DNA,RNA etc)
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Glycogen is formed through the transfer of
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Glucose from UDP glucose to a growing chain
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Complexes of oxidative phosphorylation (OP)
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NADH-Q reductase, cytochrome reductase and oxidase
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OP pumps protons from
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The matrix side > cytosolic side of the inner mito membrane
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One molecule of glucose produces about
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30 ATP when completely oxidized to CO2 and H2O
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Phosphoglycerides are phospholipids with
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A glycerol backbone with alcohol and 2 fatty acids attached
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Sphingomyelins are phospholipids with
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A sphingosine backbone with phosphoryl choline and FA
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Cholesterol functions in
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Membrane fluidity and as a precursor for steroid hormones
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Beta oxidation is the process in which (occurs in mito)
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Fatty acids are broken down into acetyl CoA groups
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1st step of beta oxidation is a – dehydration
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results in a trans double bond and 1 FADH2
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2nd step of beta oxidation involves – hydration
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Addition of H2O over the double bond – yields an alcohol
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3rd step of beta oxidation in another – dehydration
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Dehydration – carbonyl oxidized to a ketone – yields 1NADH
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4th step of beta oxidation involves - transesterification
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CoA-SH – acetyl CoA groups break off – enter TCA cycle
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First intermediate in gluconeogenesis is
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Oxalacetate – last intermediate of TCA cycle
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Ketone bodies include
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Aectoacetic acid, beta hydroxybutyrate and acetone
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Fatty acid synthesis occurs in the cytosol as a
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4 step process – 2 carbons added at a time
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Molecule used in FA synthesis for chain lengthening
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Malonate (3 carbons) – binds to –SH of acyl carrier protein
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1st step of FA synthesis – condensation
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Acetyl group adds to malonyl CoA – CO2 leaves (4C piece)
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2nd step of FA synthesis – reduction
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Requires NADPH – reduces carbonyl to an alcohol
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3rd step of FA synthesis – dehydration
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Leaves a trans double bond b/t alpha and beta carbons
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4th step of FA synthesis – reduction
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Requires NADPH – leaves a 4C saturated acyl group
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FA elongation takes place in the
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Mitochondria or SER
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Precursor to steroid hormones…
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Cholesterol – side chains removed from D ring
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Steroid hormones include
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Mineralocorticoids, glucocorticoids, androgens, estrogens, progesterone
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Purines
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Adenine and guanine
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Pyrimidines
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Thymine (DNA only), cytosine and uracil (RNA only)
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Adenine binds to
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Thymine (2 H-bonds)
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Guanine binds to
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Cytocine (3 H-bonds)
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Under physiological conditions DNA exists in the
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B form
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Termination codons
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UAA, IGA, UAG
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Initiation codon
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AUG - methionine
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DNA is super coiled in a
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Left handed helix
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Ribose contains an
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-OH (hydroxyl) group at the 2’ position (makes it less stable)
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Initiation of transccription involves a
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DNA dependent RNA polymerase
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Transcription occurs at the
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5’ end of RNA or at the 3’ end of DNA
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RNA is synthesized in a
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5’ to 3’ direction…nucleotides added at the 3’ end
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Transcription unit extends from
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Promoter to terminator
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To help protect the mRNA from hydrolytic enzymes a
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5’ cap made of modified guanosine triphosphate is added
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Ribosomes attach to the
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5’ cap
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The 3’ end of mRNA is modified with a
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Poly-A tail made of 200 adenine nucleotides
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The RNA in the nucleus contains introns and exons
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Known as heterogenous nuclear RNA (hnRNA)
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The introns are excised from the hnRNA forming
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mRNA that enters the cytoplasm
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60S ribosomal subunit contains
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5S, 5.8S and 28S rRNA
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40S ribosomal subunit contains
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18 S rRNA
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5’ end of tRNA is
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Phosphorylated
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3’ end of tRNA has a (sequence CCA)
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Hydroxyl group and an amino acid attached
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DNA replication is
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Semi conservative and bi-directional
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DNA polymerases
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Catalyze polymerization (elongation in the 5’ to 3’ direction)
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DNA ligase acts to join the
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two DNA polynucleotides through a phosphodiester bond
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Primase synthesizes the
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RNA primers needed for replication of the lagging strand
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Replication fork is unzipped by the
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ATP driven helicases
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Single standed binding proteins (SSBs)
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Keep the DNA unwound and single stranded
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The leading stand is continuously synthesized by
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DNA polymerase III holoenzyme
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The gaps between Okazaki fragments are filled by
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DNA ploymerase I (also removes the RNA primer)
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Complementary base pairs are held together by
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Hydrogen bonds
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Nucleotides are held together by
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Covalent bonds
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Transcription (DNA > RNA) takes place in the
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Nucleus
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Translation (RNA > protein) takes place in the
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Cytoplasm
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Ribosomal subunits are made in the
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Nucleolus
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P site of a ribosome holds the
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Growing ploypeptide chain
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A site of a ribosome holds the
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tRNA holding the next amino acid
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Synthesis of the polypeptide chains begins with the
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Amino end and ends with the carboxyl end
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The first tRNA with methionine (mRNA AUG)
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Attaches to the P site
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The binding of a tRNA to the A site requires
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GTP energy
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Group I hormones…
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Intracellular receptors…affect gene expression (steroids)
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Group I hormones are…
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Lipophilic, have a long half life
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Group II hormones…
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Have membrane receptors and use intracellular messengers
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Group II hormones are…
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Hydrophilic and have a short half life, use 2nd messengers
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All receptors are made of …
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Proteins
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Cyclic AMP – second messenger
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Formed by cyclization of ATP by adenylate cyclase
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Cyclic GMP – second messenger
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Used by atriopeptins found in cardiac tissues (ANF)
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