Download Irene Gold Boards Part 1-Biochemistry Exam (2024/2025) | Actual Questions and Answers Lat and more Exams Biology in PDF only on Docsity!
Irene Gold Boards Part 1-Biochemistry Exam ( 2024 /2025) | Actual Questions
and Answers Latest Updated 2024/2025 (Graded A+)
How many a.a.'s are incorporated into proteins? Answer ✔✔ 20 All a.a.'s exist in what form, EXCEPT for glycine? Answer ✔✔L-form All a.a.'s are in L-form EXCEPT for what? Answer ✔✔glycine Glycine is not in L-form because? Answer ✔✔it doesn't contain a chiral carbon define chiral carbon Answer ✔✔different compounds at each binding site All a.a's are what? Answer ✔✔amphoteric define amphoteric Answer ✔✔can act as an acid or base What are the essential a.a.'s? Answer ✔✔PVT TIM HALL phenylalanine valine tryptophan threonine isoleucine methionine histidine arginine leucine
lysine Histidine is __________________ in a child but not an adult Answer ✔✔essential What are the purely ketogenic a.a.'s? Answer ✔✔leucine and lycine What does lysine do? Answer ✔✔precursor to carnitine What does carnitine do? Answer ✔✔takes FA into mitochondria for B-oxidation What are the AROMATIC a.a.'s? Answer ✔✔phenylaline tyrosine tryptophate "Phen from house tyro-L trypt" How many of the aromatic a.a.'s are ALSO essential? Answer ✔✔ 2 What type of ring does tryptophan have? Answer ✔✔indole ring What are the sulfur-containing a.a.'s? Answer ✔✔cysteine methionine cystine Cystine is what? Answer ✔✔2 cysteines linked together What are the BRANCHED a.a.'s? Answer ✔✔isoleucine leucine
What is the a.a. derivative of: phenylalanine? Answer ✔✔tyrosine What happens when there's a deficiency of phenylalanine hydroxylase? Answer ✔✔phenylketonuria= PKU (can't covert to tyrosine) What is the a.a. derivative of: tyrosine ---> L-dopa ---> dopamine Answer ✔✔catecholamines norepinephrine epinephrine What is the a.a. derivative of: tyrosine ---> L-dopa ---> Answer ✔✔melanin (skin pigmentation) What happens if L-dopa can't convert to melanin? Answer ✔✔albinism What is the a.a. derivative of: tyrosine Answer ✔✔T3, T What is the a.a. derivative of: histidine Answer ✔✔histamine What is the a.a. derivative of: tryptophan --->serotonin Answer ✔✔melatonin What is the a.a. derivative of:
tryptophan --->niacin Answer ✔✔nicotinamide For every 10kg of body weight, how many grams of protein are needed? Answer ✔✔8 g Define Isoelectric point: Answer ✔✔pH when an a.a. has no net electrical charge (neutral) Define Zwitter ion: Answer ✔✔an a.a. at its isoelectric point Define Glutathionine: Answer ✔✔Tripeptide of glycine + glutamate + cysteine Selenium (Se) is the mineral for what? Answer ✔✔enzyme glutathione peroxidase Insulin is made up of what? Answer ✔✔2 polypeptide chains linked by disulfide bond Insulin is not part of the animal cell membrane, but helps what? Answer ✔✔helps glucose enter the cell What are compound classifications examples for polypeptide hormones? Answer ✔✔insulin glucagon What are compound classifications examples for catecholamines? Answer ✔✔epinephrine norepinephrine What are compound classifications examples for steroids? Answer ✔✔testosterone cortisol estrogen progesterone What is the characteristic bond of all proteins? Answer ✔✔peptide bond
What happens to oxygen when hemoglobin acts as an allosteric compound? Answer ✔✔oxygen will change conformational shape Disulfide bonds connect what? Answer ✔✔the light and heavy chains of an antibody All enzymes are what? Answer ✔✔catalysts Enzymes increase the ______ of a rxn by ______________________. Answer ✔✔-rate
- lowering the activation energy T/F Enzymes are not consumed in rxn. Answer ✔✔True What is the molecule which enzymes act upon? Answer ✔✔substrate Km is what? Answer ✔✔a measure of the affinity that an enzyme has towards the substrate Km and affinity have what kind of relationship? Answer ✔✔inverse (when one is low the other is higher) What is Vmax? Answer ✔✔the max velocity of the enzyme What is the relationship between Km and Vmax? Answer ✔✔Km= 1/2 Vmax What are the 3 major factors that affect the rxn velocity of an enzyme? Answer ✔✔substrate concentration temperature pH
Define Vmax: Answer ✔✔maximal velocity of an enzyme catalyzed rxn Define Km in relation to Vmax: Answer ✔✔the amount of substrate required to reach 1/2 Vmax What are competitive inhibitors? Answer ✔✔increase the Km no change in Vmax What are noncompetitive inhibitors? Answer ✔✔no change in Km decrease the Vmax Define competitive inhibitors: Answer ✔✔bind to substrate binding site of enzyme Again...what happens w/ competitive inhibitors? Answer ✔✔-increase Km (lower affinity)
- no change in Vmax
- can add enough substrate to dilute out inhibitor Define noncompetitive inhibitors: Answer ✔✔binds to site other than substrate binding site Again...what happens w/ noncompetitive inhibitors? Answer ✔✔-no change in Km: b/c affinity for binding site has not changed
- decrease in Vmax: will take longer to reach Vmax What are allosteric enzymes? Answer ✔✔act as the rate limiting steps for an entire metabolic pathway Allosteric enzyme activity is modulated by what? Answer ✔✔allosteric effectors (ex. PFK allosterically inhibited by an increase of ATP) Define Gibb's free energy: Answer ✔✔measure of the amount of energy available to determine if a rxn is energetically feasible
What are some notes for B1? Answer ✔✔-numbness of legs
- psychosis w/ dementia (not sure what Donofrio meant for this) What is the aka for B2? Answer ✔✔riboflavin What is the active form of B2? Answer ✔✔Flavin-adenine-dinucleotide (FAD) What is the reaction for B2? Answer ✔✔-redox
- dehydrogenase enzyme What are the def. disease for B2? Answer ✔✔-cheilosis
- angular stomatitis (cracking on sides) "magenta tongue" What are notes for B2? Answer ✔✔it's destroyed by light What is the aka for B3? Answer ✔✔niacin What is the active form of B3? Answer ✔✔NAD+ NADP+ Nicatinamide Adenine dinucleotide What is the reaction for B3? Answer ✔✔-redox
- dehyrdogenase enzyme
What are the def. disease for B3? Answer ✔✔-Pellagra
- 4 D's (dementia, diarrhea, dermatitis, death) Notes for B3: Answer ✔✔Tryptophan ---> niacin ---> nicatinamide What is the active form of B5? Answer ✔✔pantothenate What is the reaction for B5? Answer ✔✔structural component of CoA What is the def. disease for B5? Answer ✔✔burning foot syndrome (parasthesias) Note for B5: Answer ✔✔heat labile What is the aka for B6? Answer ✔✔pyridoxine What is the active form of B6? Answer ✔✔pyridoxal- 5 - phosphate What is the reaction for B6? Answer ✔✔1. Transanimations Ketoacid <--> Amino Acid
- a.a. metabolism Notes for B6: Answer ✔✔made by flora What is the aka for B7? Answer ✔✔biotin What is the active form of B7? Answer ✔✔Biocytin What is the reaction for B7? Answer ✔✔-Carboxylation (-CO2)
Notes for B12: Answer ✔✔-contains cobalt
- mainly in animal products (lacking in vegetarian diet) What is the AKA for Vit C? Answer ✔✔Ascorbic Acid What is the reaction for Vit C? Answer ✔✔Hydroxylation of proline and lysine in collagen (enhances Iron absorption) What is the def. disease for Vit C? Answer ✔✔Scurvy (bleeding gums) Proline --> Hydroxyproline -->Fe3+ -->Fe2+ Notes for Vit C: Answer ✔✔-destroyed by heat
- brussel sprouts=one of the highest sources What are Fat Soluble Vitamins classified as? Answer ✔✔isoprenes OR isoprenoids What are the fat soluble vitamins? Answer ✔✔Vit A, Vit D, Vit E, Vit K KADE What is the active form of Vit A? Answer ✔✔retinal retinoid acid = most active form What is the function of Vit A? Answer ✔✔vision, growth What are the def. diseases of Vit A? Answer ✔✔-night blindness = 'nyctalopia'
- keratomalacia = degeneration of the cornea
- xerophthalmia = dry eyes Note for Vit A: Answer ✔✔vitamin for the immune system What is the active form for Vit D? Answer ✔✔1, 25-dihydroxy-cholecalciferol What is the function of Vit D? Answer ✔✔calcium and phosphate metabolism What are the def. disease for Vit D? Answer ✔✔Rickets in young Osteomalacia in adults Notes for Vit D: Answer ✔✔the body can make it What is the active form of Vit E? Answer ✔✔alpha-tocopherol What is the function of Vit E? Answer ✔✔lipid antioxidant What is the def. disease for Vit E? Answer ✔✔excess = diarrhea Note for Vit E? Answer ✔✔best source = wheat germ oil What are aka's for Vit K? Answer ✔✔hydroquinone OR Menadione What is the best source of Vit K? Answer ✔✔green leafy vegetables
What are the functions for iodine? Answer ✔✔-thyroxine (T4)
- triiodothyronine(T3) What is the metabolism for iodine? Answer ✔✔stored as thyroglobulin What is the def. disease/symptoms for iodine? Answer ✔✔children: cretinism adults: goiter, myxedema What are the functions of Iron? Answer ✔✔Heme enzymes: hemoglobin, cytochromes What is the metabolism for Iron? Answer ✔✔transported= transferrin stored = ferritin What is the deficiency disease or symptoms for Iron? Answer ✔✔hypochromic microcytic anemia What are the functions of selenium? Answer ✔✔cofactor, glutathione peroxidase What is the metabolism for selenium? Answer ✔✔antioxidant What is the function for Zinc? Answer ✔✔cofactor, carbonic anydrase What is the metabolism for zinc? Answer ✔✔immune system taste wound healing prostate What is the deficiency disease or symptoms for zinc? Answer ✔✔impaired wound healing
What is the function of fluoride? Answer ✔✔increase hardness of teeth What is the deficiency disease or symptoms for Fluoride? Answer ✔✔deficiency = dental carries excess = hyperfluorsis Methylation Cycle Answer ✔✔pg 9 in packet B12 gives methyl group to what? Answer ✔✔homocysteine B9 gives methyl group to what? Answer ✔✔B B9 deficiency affects what? Answer ✔✔B12 and vice versa B12 deficiency causes which anemia? Answer ✔✔-#1 pernicious anemia (if from low intrinsic factor)
- megaloblastic anemia (vegetarians) What happens if you're deficient in B Vit's during remethylation cycle? Answer ✔✔you will create a methionine deficiency Vit D synthesis Answer ✔✔pg 9 in packet Iron Absorption Answer ✔✔pg 9 in packet Fe 3+ aka Answer ✔✔Ferric MOST ACTIVE in food and used in body Fe2+ aka Answer ✔✔Ferrous
- Where is the Carbonyl (C=O) group? Carbon #1 = aldo (aldehyde) Carbon #2 = keto (ketone) The most relevant monosaccharides have how many C's? Answer ✔✔5 (pentose) 6 (hexose) What is the monosaccharide name for glucose? Answer ✔✔aldohexose What is the monosaccharide name for galactose? Answer ✔✔aldohexose What is the monosaccharide name for mannose? Answer ✔✔aldohexose What is the monosaccharide name for ribose? Answer ✔✔aldopentose What is the monosaccharide name for fructose? Answer ✔✔ketohexose What is the Monosaccharide formula? Answer ✔✔Cn(H2O)n n= # of C's ex. ketopentose = C5H10O aldohexose(glucose) = C6H12O Define Isomers: Answer ✔✔different compounds w/ the same chemical formula (Glucose, Fructose & Galactose) (C6H1206) Define Epimers: Answer ✔✔Monosaccharides which differ in their configuration around one specific C Glucose and Galactose are what? Answer ✔✔C-4 epimers
Glucose and Mannose are what? Answer ✔✔C-2 epimers Define Enantiomers: Answer ✔✔mirror images of the same compound (L and D-glucose) Define Anomers: Answer ✔✔Anomeric C's are formed when sugars cyclize What is the anomeric carbon for aldehyde (glucose, galactose)? Answer ✔✔C- 1 What is the anomeric carbon for a ketosugar(fructose)? Answer ✔✔C- 2 What are the two designations for anomers? Answer ✔✔alpha OR beta Describe the Fischer projection in regards to representations of monosaccharides: Answer ✔✔linear stick figure Describe the Haworth projection in regards to representations of monosaccharides: Answer ✔✔cyclized form (eg. picture of ribose and deoxyribose) What is sucrose made up of and what is their linkage? Answer ✔✔glucose + fructose Linkage: alpha 1, beta 2 What is lactose made up of and what is it's linkage? Answer ✔✔galactose + glucose Linkage: beta 1, 4 What is maltose made up of and what is it's linkage? Answer ✔✔glucose + glucose
