Biochemistry Review Q's Flashcards
LECTURES 1. Muscle Biochemistry (1-27) SEMINARS: 1. Proteoglycan & Biochemistry of Joints (28-44) 2. Mitochondrial genome: Biogenesis & Defects (45-60)
Which of the following sources of ATP do you use when you suddenly run from class because of a fire alarm?
a. aerobic
b. anaerobic
b. anaerobic
Why is chicken meat white?
a. no fat
b. no ATP
c. no mitochondria
c. no mitochondria
Which of the following muscles is used by a long-distance runner?
a. largest diameter muscles
b. fast-twitch
c. slow-twitch
c. slow-twitch
Which of the following is used by muscles at rest?
a. fatty acids
b. glucose
c. glycogen
a. fatty acids
Which of the following muscles is used by a weight lifter?
a. smallest diameter muscles
b. fast-twitch
c. slow-twitch
b. fast-twitch
Inhibition of glucose utilization is strongest at which level?
a. PFK-1
b. PFK-2
c. PDH
c. PDH
What inhibits PFK-1?
a. citrate accumulation
b. acetyl-CoA
c. NADH
a. citrate accumulation
What’s a commonly used as a measure of kidney function?
a. creatinine
b. citrate
c. carnitine
a. creatinine
What does the body do when the ATP is high?
a. inhibits malonyl coA
b. inhibits carnitine transferase I
c. inhibits carnitine transferase II
b. inhibits carnitine transferase I
Which enzyme is directly inibited by high ATP levels?
a. creatine phosphate
b. adenylate kinase
c. isocitrate dehydrogenase
c. isocitrate dehydrogenase
Which of the following provides an ATP molecule?
a. creatine phosphate
b. creatine kinase
c. isocitrate dehydrogenase
b. creatine kinase
Which of the following carries a high energy phosphate from the mitochondria to myosin filaments?
a. creatine phosphate
b. creatine kinase
c. isocitrate dehydrogenase
a. creatine phosphate
When is ATP-CP Anaerobic Energy Pathway used?
a. 40-minute walk
b. short sprint
b. short sprint
Which of the following provides an ATP molecule using two ADP molecules?
a. adenylate kinase
b. creatine kinase
c. isocitrate dehydrogenase
a. adenylate kinase
Which of the following activates glycogen phosphorylase b?
a. AMP
b. Ca+2
c. cAMP
d. epinephrine
a. AMP
Which of the following is used to fuel fast-twitch muscle fibers?
a. anaerobic glycolysis
b. aerobic glycolysis
a. anaerobic glycolysis
What activates fatty acid oxidization?
a. higher melonyl coA
b. higher acetyl coA carboxylase
c. AMP
c. AMP
Which of the following inhibits phosphoprotein phosphatase?
a. AMP
b. Ca+2
c. cAMP
d. epinephrine
c. cAMP
Which of the following bind to calmodulin to activate phosphorylase kinase?
a. AMP
b. Ca+2
c. cAMP
d. epinephrine
b. Ca+2
Which of the following would happen to glycogen stores overnight?
a. they decrease by 30%
b. they decrease by 80%
c. they stay the same
c. they stay the same
Which of the following is used to eliminate nitrogen?
a. cori cycle
b. glucose alanine cycle
b. glucose alanine cycle
Which of the following is used for high-intensity exercises?
a. carbohydrates
b. fatty acids
a. carbohydrates
Glycogen degradation of which area is activated by glucagon?
a. liver
b. muscle
c. both
d. neither
a. liver
Glycogen degradation of which area is activated by AMP?
a. liver
b. muscle
c. both
d. neither
b. muscle
Which of the following makes a higher number of ATP molecules?
a. anaerobic glycolysis
b. oxidative phosphorylation
b. oxidative phosphorylation
Which of the following has a higher amount of glycolytic enzymes?
a. fast-twitch glycolytic fibers
b. slow-twitch glycolytic fibers
a. fast-twitch glycolytic fibers
Which of the following is used to recycle lactate?
a. cori cycle
b. glucose alanine cycle
a. cori cycle
Which of the following GAG types is longer?
a. chondroitin sulfate
b. keratan sulfate
a. chondroitin sulfate
How are core proteins linked to hyaluronic acid?
a. linker protein
b. covalent bond
a. linker protein
Where are large aggregates of proteoglycan found?
a. synovial fluid
b. pericellular matrix
c. intracellular matrix
d. extracellular matric
c. intracellular matrix
Which of the following is used to treat/modify the joint damage caused by osteoarthritis?
a. glucosamine
b. glucosamine-6-phosphate
c. both
d. neither
d. neither
Which of the following is a proven effect of Glucosamine?
a. articular cartilage restoration
b. anti-inflammatory effect
b. anti-inflammatory effect
Many markets cell oral Glucosamine. Where do they extract it from?
mainly derived from chitin in crustacean shells
What kind of person is not allowed to consume oral Glucosamine?
A person with a shellfish allergy
Which is the major proteoglycan that makes up cartilage?
aggrecan
Patient presents with joint pain, swelling, and stiffness.
CBC indicates absence of neutrophils. Synovitis is present as well as in infiltration of activated B cells, T lymphocytes, and overexpression of proinflammatory mediators. What’s most likely?
a. rheumatoid arthritis
b. osteoarthritis
b. osteoarthritis
Which has high neutrophil count?
a. rheumatoid arthritis
b. osteoarthritis
a. rheumatoid arthritis
How do you diagnose osteoarthritis using biomarkers?
Monoclonal antibodies have been developed that recognize products of proteoglycan or collagen degradation
Which has low neutrophil count?
a. rheumatoid arthritis
b. osteoarthritis
b. osteoarthritis
Which of the following is helpful in detecting early cases of osteoarthritis?
a. MMP
b. ADAMT
c. TIMPS
d. GAGs
d. GAGs
glucosaminoglycans
Which of the following occurs first?
a. release of glucosaminoglycans
b. appearance of collagen fragments
a. release of glucosaminoglycans
How are disaccharide residues linked with core proteins?
through serine or threonine residues using a galactose-galactose-xylose trisaccharide link
Which collagen fiber is the most available in cartilage?
a. type 1
b. type 2
c. type 5
d. type 6
b. type 2
How are glycosaminoglycans (GAG) linked to core proteins?
a. linker protein
b. covalent bond
b. covalent bond
T/F: most mitochondrial DNA encodes for tRNA’s
true, 22 out of the 37 encode for tRNA
Which is circular DNA?
a. mitochondrial DNA
b. nuclear DNA
a. mitochondrial DNA
Which is mostly non-coding?
a. mitochondrial DNA
b. nuclear DNA
b. nuclear DNA
Which has a haploid inheritance patter?
a. mitochondrial DNA
b. nuclear DNA
a. mitochondrial DNA
Which follows a relaxed replication?
a. mitochondrial DNA
b. nuclear DNA
a. mitochondrial DNA
Why is mitochondrial DNA more susceptible to damage?
no protection, more ROS exposure, bad repair mechanisms
Which of the following is due to mutations in the tRNA leucine gene?
a. MERRF
b. MMIT
c. MELAS
c. MELAS
Which of the following is due to mutations in the tRNA lysine gene?
a. MERRF
b. MMIT
c. MELAS
a. MERRF
Which of the following is due to mutations in the tRNA glutamic acid gene?
a. MERRF
b. MMIT
c. MELAS
b. MMIT
Mutations in which mitochondrial DNA genes cause neuromuscular myopathy?
a. tRNA genes
b. rRNA genes
c. protein-coding genes
a. tRNA genes
What are the first areas to be affected when ATP production is decreased?
brain and muscles
Why isn’t paternal mitochondria utilized?
a. paternal mitochondria gets eliminated by autophagy
b. paternal mitochondria does not enter the egg
c. paternal mitochondria is defective
a. paternal mitochondria gets eliminated by autophagy
What does a positive COX test indicate?
when positive, it indicates a normal efficiency of oxidative phosphorylation (cytochrome C oxidase high) and ATP synthesis
What does a positive COX test look like?
a. white color
b. red color
c. brown color
c. brown color
Which stain is used to see red ragged muscle fibers?
Gomori Trichrome
Describe the pH of tissue in a patient with mitochondrial myopathy?
a. high pH
b. low pH
b. low pH
lactic acidosis
What’s the key substrate for purine synthesis?
PRPP (5-phosphoribosyl-1-pyrophosphate)
what two things inhibit PRPP synthetase?
ADP & GDP
what two things inhibit GPAT enzyme?
AMP & GMP
Which of the following is used to make AMP?
a. ATP
b. GTP
c. NAD
b. GTP
Which of the following is used to make GMP?
a. ATP
b. GTP
c. aspartic acid
a. ATP
Which enzyme makes an ATP out of 2 ADP’s?
a. ribonucleotide reductase
b. adenylate kinase
d. AMP deaminase
b. adenylate kinase
What does the purine nucleotide cycle produce?
NH4 (ammonium) and Fumarate
Which enzyme makes nucleotides into deoxynucleotides?
a. ribonucleotide reductase
b. adenylate kinase
d. AMP deaminase
a. ribonucleotide reductase
What enzyme converts AMP to IMP? and what does it release from this conversion?
AMP deaminase. it releases NH4
T/F: purines and pyrimidine catabolism is done by converting them to uric acid then excretion
false, pyrimidine is not made into uric acid. It’s ultimately catabolized (degraded) to CO2
Inactivity of which enzyme causes fatigue of skeletal muscle during exercise?
a. ribonucleotide reductase
b. adenylate kinase
d. AMP deaminase
d. AMP deaminase
T/F: uric acid has antioxidant properties
true
What is the majority of uric acid excreted into?
a. urine
b. feces
a. urine
Which of the following is the favored form at pH 7.4?
a. uric acid
b. urate anion
b. urate anion
Which best describes the urate solubility?
a. more soluble with high ph
b. more soluble at low ph
c. more soluble at colder temperatures
a. more soluble with high ph
Which of the following have a higher uric acid solubility?
a. men
b. women
a. men
What’s the major cause of hyperuricemia?
a. excess meat consumption
b. overproduction of uric acid
c. under excretion of uric acid
c. under excretion of uric acid
7 y/o boy comes in with compulsive self-mutilation of the head and hands, learning difficulties and involuntary muscular movements. What’s the diagnosis?
Lesch-Nyhan syndrome
What things activates the GPAT enzyme?
high PRPP
What does NOT cause higher purine?
a. higher PRPP synthase
b. HGPRT deficiency
c. lower r6p
c. lower r6p
(A= PRPP is a positive activator of GPAT, which is an enzyme in the purine synthesis pathway B= HGPRT is part of the salvage pathway, which uses PRPP. If it'd deficient and not using PRPP, PRPP build up and activates GPAT C= R6P is a driver of the formation of PRPP)
What is identified as a therapeutic target of gout?
IL-1b
How does probenecid help treat gout?
it increases renal clearance by acting on URAT1 receptor
probenecid acts on which transporter?
a. OAT1
b. ABCG2
c. URAT1
d. SLC2A
e. MRP4
c. URAT1
Describe the relationship between allopurinol and hypoxanthine.
a. they function similarly
b. they have similar structures
c. irreversible inhibition
b. they have similar structures
allopurinol is an analog of hypoxanthine
Describe the relationship between allopurinol and xanthine oxidase.
a. they function similarly
b. they have similar structures
c. irreversible inhibition
c. irreversible inhibition
allopurinol attaches because it looks like hypoxanthine, but then it stops the enzyme from working and doesn’t let go
Consumption of which of the following can trigger gout?
a. cigarettes
b. candy
c. energy drink
d. all of the above
d. all of the above
(ethanol in cigarettes and fructose in candy & energy drinks can build up AMP and break down purine leading to high uric acid)
What elevates lactic acid levels?
high G6P high AMP high R5P reduced HGPRT reduced APRT
The most common cell that creates collagen is
fibroblasts
What collagen type can act as a filter?
a. fibril forming
b. network forming
c. fibril associated
b. network forming
Which collagen type is most available?
a. 1
b. 2
c. 3
d. 4
e. 5
f. 6
g. 7
a. 1
Which collagen type is used to make ligaments or tendons?
a. 1
b. 2
c. 3
d. 4
e. 5
f. 6
g. 7
g. 7
The alpha chain structure is Gly-X-Y. Which of the following often represents X?
a. glycine
b. hydroxyproline
c. proline
d. adenine
c. proline
Which of the following parts of the alpha chain structure induces a kink?
a. glycine
b. hydroxyproline
c. proline
d. adenine
c. proline
Which of the following parts of the alpha chain structure is the smallest?
a. glycine
b. hydroxyproline
c. proline
d. adenine
a. glycine
The alpha chain structure is Gly-X-Y. Which of the following often represents Y?
a. glycine
b. hydroxyproline
c. proline
d. adenine
b. hydroxyproline
Which of the following can act to facilitate hydrogen bonding to the triple helix molecule?
a. hydroxyproline residue
d. hydroxylysine residue
a. hydroxyproline residue
What do the prolyl and lysyl hydroxylase enzymes need to function?
alpha-ketoglutarate and vitamin C
Which of the following prevents excessive flexibility of chains?
a. glycine
b. hydroxyproline
c. proline
d. adenine
c. proline
Which can serve as the attachment point for glycosylation?
a. hydroxyproline residue
d. hydroxylysine residue
d. hydroxylysine residue
What can act as a collagen synthesis marker?
hydroxyproline residue
hydroxylysine residue
What happens to the alpha chains if hydroxyproline residue is lost?
it then has less strength because hydroxyproline helps make hydrogen bonds, which makes it more powerful
Where are procollagen chains made?
a. ER lumen
b. RER
c. Golgi
d. Extracellular space
e. Vesicles
b. RER
Where is tropocollagen made?
a. ER lumen
b. RER
c. Golgi
d. Extracellular space
e. Vesicles
d. Extracellular space
Where is the triple helix assembled?
a. ER lumen
b. RER
c. Golgi
d. Extracellular space
e. Vesicles
a. ER lumen
&
c. Golgi
covalent crosslinking is done by which enzyme
lysine oxidase
Which enzyme acts extracellularly?
a. prolyl hydroxylase
b. lysyl hydroxylase
c. lysine oxidase
c. lysine oxidase
procollagen peptidase also works extracellularly
What type of links occurs when two allysine molecules bind?
a. schiff base link
b. aldol link
b. aldol link
Whats is allysine? and how to we make it?
its a derivative of lysine produced by lysyl oxidase enzyme in the extracellular matrix
Which enzyme needs copper to function?
a. procollagen peptidase
b. lysine oxidase
c. hydroxylase
b. lysine oxidase
What type of links occurs when lysine and allysine bind?
a. schiff base link
b. aldol link
a. schiff base link
T/F: generally speaking the life span of collagen fibers is short
false, collagen is very stable and can last for up to several years
If a patient had high hydroxyproline in their urine, what can you assume?
high collagen degradation
What do you call fibroblasts inside tendons?
tenocytes
What is an adhesive molecule that’s associated with cell junctions?
fibronectin (binds collagens and integrins)
T/F: after a tendon fully heals from an injury, and crosslinks are formed, then tendon returns to its previous strength before the injury
false, it becomes 30% weaker
Which enzyme is affected when a patient has scurvy?
a. procollagen peptidase
b. lysine oxidase
c. hydroxylase
c. hydroxylase
Which enzyme is affected when a patient eats too many Lathyrus odoratus?
a. procollagen peptidase
b. lysine oxidase
c. hydroxylase
b. lysine oxidase
“collagen suicide” is found in which inherited disorder?
OI
Which collagen type is affected by epidermolysis bullosa?
a. 1
b. 2
c. 3
d. 4
e. 5
f. 6
g. 7
g. 7
Which TWO collagen types are affected in EDS?
a. 1
b. 2
c. 3
d. 4
e. 5
f. 6
g. 7
a. 1
&
c. 3