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NBCE - Part 1 / Biochemistry - Irene Gold Review Questions with complete & Updated Solutio, Exams of Biochemistry

NBCE - Part 1 / Biochemistry - Irene Gold Review Questions with complete & Updated Solution

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NBCE - Part 1 / Biochemistry - Irene Gold Review
Questions with complete & Updated Solutions
All amino acids are L-form except? - Answer ✔️✔️-glycine
T/F - All amino acids are amphoteric? - Answer ✔️✔️-T
What does amphoteric mean? - Answer ✔️✔️-Can act as either an acid or a base
What are the essential amino acids? - Answer ✔️✔️-P = phenylalanine
V = valine
T = tryptophan
T = threonine
I = isoleucine
M = methionine
H = histidine
A = arginine
L = leucine
L = lycine
T/F - histidine is essential in a child but not an adult? - Answer ✔️✔️-True
What are the purely ketogenic amino acids? - Answer ✔️✔️-Leucine and Lysine
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Download NBCE - Part 1 / Biochemistry - Irene Gold Review Questions with complete & Updated Solutio and more Exams Biochemistry in PDF only on Docsity!

NBCE - Part 1 / Biochemistry - Irene Gold Review

Questions with complete & Updated Solutions

All amino acids are L-form except? - Answer ✔️ ✔️ -glycine

T/F - All amino acids are amphoteric? - Answer ✔️ ✔️ -T

What does amphoteric mean? - Answer ✔️ ✔️ -Can act as either an acid or a base

What are the essential amino acids? - Answer ✔️ ✔️ -P = phenylalanine

V = valine

T = tryptophan

T = threonine

I = isoleucine

M = methionine

H = histidine

A = arginine

L = leucine

L = lycine

T/F - histidine is essential in a child but not an adult? - Answer ✔️ ✔️ -True

What are the purely ketogenic amino acids? - Answer ✔️ ✔️ -Leucine and Lysine

What amino acid is the precursor for carnitine? - Answer ✔️ ✔️ -Lysine

What is the function of carnitine? - Answer ✔️ ✔️ -takes FA into mitochondria for beta-oxidation

What are the aromatic amino acids? - Answer ✔️ ✔️ -phenylalanine

tyrosine

tryptophan

What is unique about tryptophan? - Answer ✔️ ✔️ -It has an indole ring

What are the sulfur-containing amino acids? - Answer ✔️ ✔️ -cysteine, methionine, and cystine

2 cysteines linked together make what? - Answer ✔️ ✔️ -cysteine

What are the branched chain amino acids? - Answer ✔️ ✔️ -isoleucine, leucine and valine

Maple syrup urine disease is a defect in? - Answer ✔️ ✔️ -the bodies ability to breakdown branched chain amino acids

What are the acidic amino acids? - Answer ✔️ ✔️ -aspartate and glutamate

What does aspartame contain that makes it neurotoxic in excess? - Answer ✔️ ✔️ - aspartic acid (aspartate)

What are the basic amino acids? - Answer ✔️ ✔️ -histidine, lysine and arginine

T/F - basic amino acids have the smallest positive net charge at NORMAL pH of blood? - Answer ✔️ ✔️ -F - greatest positive net charge

What is nicotinamide derived from? - Answer ✔️ ✔️ -Tryptophan --> niacin --> nicotinamide

For every 10 kg of body wt, how many grams of protein does a person need? - Answer ✔️ ✔️ - 8 g

What is the isoelectric point? - Answer ✔️ ✔️ -pH when an amino acid has no net electrical charge (neutral)

What is a zwitter ion? - Answer ✔️ ✔️ -an amino acid at its isoelectric point

What is glutathione? - Answer ✔️ ✔️ -tripeptide of glycine + glutamate + cysteine

What is selenium?. - Answer ✔️ ✔️ -mineral for enzyme glutathione peroxidats

What is insulin? - Answer ✔️ ✔️ - 2 polypeptide chains linked by disulfide bonds

  • not part of animal cell membrane, but helps glucose enter the cell

What are two examples of polypeptide hormones that function in opposition? - Answer ✔️ ✔️ -insulin & glucagon

What are two examples of catecholamines that function in opposition? - Answer ✔️ ✔️ - epinephrine & norepinephrine

What are examples of steroids? - Answer ✔️ ✔️ -testosterone, cortison, estrogen, progesterone

What is the characteristic bond of a protein? - Answer ✔️ ✔️ -peptide bond - type of amide bond that is specific for proteins (peptide bond aka C=N or carboxyl-amino bon

What is the primary protein structure? - Answer ✔️ ✔️ -linear sequence of aa

What is the secondary structure of a protein? - Answer ✔️ ✔️ -alpha-helix & beta- pleated sheets

  • held together by hydrogen bonds between atoms of polypeptide backbone

What are examples of secondary structures of proteins? - Answer ✔️ ✔️ -fibrous protein's collagen and silk; 2 dna strands together

What is a tertiary protein structures? - Answer ✔️ ✔️ -Folding of a single polypeptide chain in solution.

What are examples of tertiary protein structures? - Answer ✔️ ✔️ -- myoglobin

  • disulfide bonds

What is a quaternary protein structure? - Answer ✔️ ✔️ -Association of two or more polypeptide chains to make a functional protein

What is the classic example of a quaternary structure? - Answer ✔️ ✔️ -- hemoglobin

  • hydrogen and disulfide bonds

What is an allosteric compound and an example? - Answer ✔️ ✔️ -a compound that changes conformational shape

  • hemoglobin will change when oxygen binds to it

What type of bond connects the light and heavy chains of an antibody? - Answer ✔️ ✔️ - disulfide bond

What is the Km of an enzymatic rxn? What is the relationship? - Answer ✔️ ✔️ -- a measure of the affinity that an enzyme has towards the substrate

  • inverse relationship = the lower the Km, the higher the affinity

- FAD

  • Oxidation/reduction dehydrogenase enzyme
  • Cheilosis, angular stomatitis, magenta tongue
  • destroyed by light

B3 - Answer ✔️ ✔️ -- niacin

  • NAD, NADP, nicatinamide, adenine dinucleotide
  • redox rxn
  • Pellegra
  • 4 D's: dementia, diarrhea, dermatitis, death
  • tryptophan (T) --> niacin --> nicatinamide

B5 - Answer ✔️ ✔️ -- pantothenate

  • structural component of coenzyme A (CoA)
  • burning foot syndrome (parasthesias)
  • heat labile

B6 - Answer ✔️ ✔️ -- pyridoxine

  • pyridoxal- 5 - phosphate
  1. transamination; ketoacid <-> amino acid
  2. amino acid metabolism
  • made by flora

B7 - Answer ✔️ ✔️ -- biotin

  • biocytin
  • carboxylation (+CO2); eg acetyl-coA carboxylase (lipogenesis)
  • avidin in egg whites depletes biotin
  • intestinal bacterial make

B9 - Answer ✔️ ✔️ -- folic acid

  • tetrahydrofolate
  • one carbon transfers (methyl transfer)
  • DNA & RNA synthesis
  • megaloblastic anemia
  • glossitis
  • neural tube defects --> spina bifida

B12 - Answer ✔️ ✔️ -- cobalamin

  • methylcobalamin
  • homocysteine remethylation
  • pernicious anemia from decreased intrinsic factor
  • PLS: posterior lateral sclerosis AKA combined systems disease
  • B12 deficiency from any other cause is megaloblastic anemia (eg vegetarians)
  • contains cobalt
  • mainly in animal products

Vit C - Answer ✔️ ✔️ -- ascorbic acid

  • lipid antioxidant
  • excess = diarrhea
  • best source is wheat germ oil

Vit K - Answer ✔️ ✔️ -- hydroquinoine

  • menadione
  • best source = green leafy veg
  • blood clotting
  • precursor for conenzyme Q
  • def = clotting time
  • converts prothrombin to thrombin
  • made by fora

Chromium - Answer ✔️ ✔️ -- glucose tolerance factor

  • helps bind insulin to cell
  • impaired glucose tolerance

Cobalt - Answer ✔️ ✔️ -- constituent of vitamin B 12

  • pernicious anemia

Magnesium - Answer ✔️ ✔️ -- binds to ATP

  • muscle contraction/relax
  • protein production
  • many enzymes
  • mg/ca ration 1:
  • hyperexcitability
  • muscle weakness
  • sleepness

Iodine (I) - Answer ✔️ ✔️ -- thyroxine (T 4 )

  • triiodothyronine (T3)
  • stored as thyroglobulin
  • children: cretinsim
  • adults: goiter, myxedema

Iron (Fe) - Answer ✔️ ✔️ -- heme enzymes, hemoglobin, cytochromes

  • transported transferrin
  • stored ferritin
  • Hypochromatic microcytic anemia

Selenium (Se) - Answer ✔️ ✔️ -- cofactor

  • glutathione peroxidase
  • antioxidant

Zinc ( Zn) - Answer ✔️ ✔️ -- cofactor

  • carbon anhydrase
  • immune system
  • taste

what is the active form of vitamin D? - Answer ✔️ ✔️ -1,25 dihydroxycholecalciferol (vit D3)

What is the most active form of iron? - Answer ✔️ ✔️ -Fe 3 + = ferric

What is the most absorbable form of iron? - Answer ✔️ ✔️ -Fe 2 + = ferrous

What is the pathway of iron in the body? - Answer ✔️ ✔️ -Fe3+ (in food) --->(vit C) Fe2+ (absorbed in intestines) --> Fe 3+ (used in body)

What vitamins are considered antioxidants? - Answer ✔️ ✔️ -Vitamin A, C, E and Selenium

What do glutathione, lipoic acid and CoQ10 all have in common? - Answer ✔️ ✔️ - They are all antioxidants

What is the function of PTH? - Answer ✔️ ✔️ -increases serum calcium

What is the function of calcitonin? - Answer ✔️ ✔️ -decreases serum calcium

Monosaccharides are characterized into what two groups? - Answer ✔️ ✔️ - aldehydes or ketones

What carbon number is the aldehyde group always on? - Answer ✔️ ✔️ -carbon 1

What carbon number is ketone on in carbohydrate? - Answer ✔️ ✔️ -carbon 2

Glucose and galactose are what type of epimer? - Answer ✔️ ✔️ -C- 4

glucose and maltose are what type of epimer? - Answer ✔️ ✔️ -C- 2

Anomer - Answer ✔️ ✔️ -anomeric carbons are formed when sugars cyclize; either alpha or beta

sucrose is made up of... - Answer ✔️ ✔️ -glucose & fructose (alpha 1 , beta 2 )

lactose is made up of... - Answer ✔️ ✔️ -galactose + glucose (beta 1,4)

Maltose is made up of - Answer ✔️ ✔️ -glucose + glucose (alpha 1,4)

Isomaltose is made up of... - Answer ✔️ ✔️ -glucose + glucose (alpha 1,6)

cellobiose is made up of .... - Answer ✔️ ✔️ -glucose + glucose (beta 1,4)

What bond can lactase break? - Answer ✔️ ✔️ -beta 1,

What bond can amylase break - Answer ✔️ ✔️ -alpha 1 , 4 into maltose

What does amylopectin break into? - Answer ✔️ ✔️ -maltose and isomaltose

What does amylose break into? - Answer ✔️ ✔️ -just maltose

Glycogen contains what type of bonds? - Answer ✔️ ✔️ -alpha 1,4 and alpha 1,

amylose contains what type of bonds? - Answer ✔️ ✔️ -alpha 1,

amylopectin contains what type of bonds? - Answer ✔️ ✔️ -alpha 1,4 and alpha 1, 6

cellulose contains what type of bonds? - Answer ✔️ ✔️ -beta 1,4 (fiber)

What is the most common GAG? - Answer ✔️ ✔️ -hyaluronic acid & chondroitin sulfate

Where is hyaluronic acid found? - Answer ✔️ ✔️ -synovial fluid

Where is chondroitin sulfate found? - Answer ✔️ ✔️ -cartilage, tendons, ligaments

Ester bond? - Answer ✔️ ✔️ -acid + alcohol

What is the most saturated oil and therefore the least likely to become rancid? - Answer ✔️ ✔️ -coconut oil

What oil is primarily found in olive oil? - Answer ✔️ ✔️ -oleic acid (omega- 9 )

What are the saturated fats and how many carbons do they have? - Answer ✔️ ✔️ - lauric acid - 12

myristic acid - 14

palmitic - 16

stearic - 18

What are the unsaturated fats? How many carbons do they have? How many double bonds? - Answer ✔️ ✔️ -Oleic Acid; 18 ; 1 C=C

linoleic; 18; 2 C=C

Linolenic ( alpha and gamma); 18; 3 C=C

Arachidonic; 20 4 C=C

What are the 2 main classes of nonglycerol lipids? - Answer ✔️ ✔️ -- sphingolipids

  • steroids

Where is sphingomyelin found? - Answer ✔️ ✔️ -major lipid component in myelin

What happens when a person has a deficiency in sphingomyelinase? - Answer ✔️ ✔️ - Niemann-Pick disease

What is the most abundant sterol in humans? - Answer ✔️ ✔️ -cholesterol; derived from acetyl CoA

HMG-CoA reductase - Answer ✔️ ✔️ -- rate-limiting enzyme of cholesterol synthesis

  • converts HMG-CoA to mevalonate

What is the rate-limiting enzyme in steroid biosynthesis? - Answer ✔️ ✔️ -- desmolase

  • converts cholesterol --> pregnenolone

What function does fiber have in the elimination of cholesterol - Answer ✔️ ✔️ -fiber binds biles salts

What is the rate limiting enzyme of ketone body synthesis? - Answer ✔️ ✔️ -HMG- CoA synthase

Chylomicron - Answer ✔️ ✔️ -- produced & secreted from intestinal mucosal cells

  • produced in response to dietary intake of fat
  • carry triacylglycerides to peripheral tissues

VLDL - Answer ✔️ ✔️ -- synthesized and secreted from liver

  • transports triacylglycerides to peripheral tissues from teh liver

LDL - Answer ✔️ ✔️ -- derived from VLDL

  • transport cholesterol from the liver to peripheral tissues
  • contains great amounts of cholesterol

HDL - Answer ✔️ ✔️ -- synthesized & secreted from the liver

  • transports cholesterol from peripheral tissues back to the liver

What is the base pairing for DNA? RNA? - Answer ✔️ ✔️ -At The Golf Course

A-T

G-C

A-U

G-C

Phosphodiester bonds - Answer ✔️ ✔️ -- 3 prime carbon in one sugar w/ 5 prime carbon of another

  • covalent bonds

Replication - Answer ✔️ ✔️ -- DNA --> DNA

  • nucleus
  • S phase
  • 5 prime - > 3 prime
  • antiparallel
  • DNA polymerase

Transcription - Answer ✔️ ✔️ -- DNA --> mRNA

  • 5 prime - > 3 prime
  • every 3 bases = codon
  • codon codes 1 aa
  • RNA Polymerase
  • 1st aa always codes methionine
  • START AUG, GUG
  • STOP: UAA, UGA, UAG

Translation - Answer ✔️ ✔️ -- mRNA --> protein

  • cytoplasm
  • rough ER
  • peptidyl transferase links 2 aa together

Protein synthesis - Answer ✔️ ✔️ -- ribosome reads mRNA 5 prime --> 3 prime

  • N term to C term

reverse transcription - Answer ✔️ ✔️ -- RNA back to DNA

Cori Cycle - Answer ✔️ ✔️ -- anaerobic

  • muscle & liver
  • glucose in muscle converted to 2 molecules of lactate
  • lactate to liver
  • lactate converted to glucose in liver

Pyruvate dehyrogenase complex - Answer ✔️ ✔️ -- mitochondrial matrix

  • pyruvate --> acetyl-CoA
  • oxidative decarboxylation
  • stimulated by insulin,