Biochem Exam 2 Review

Front 1

What is the difference between proteoglycans and glycoproteins?

Back 1

Proteoglycans - Glycosaminoglycan chains (contains repeating disaccharides)

Glycoproteins - Oligosaccharide chains (no repeating disaccharides)

Front 2

All glycosaminoglycans except hyaluronic acid are synthesized where?

Back 2

Golgi

Hyaluronic acid synthesized in plasma membrane

Front 3

Main locations of hyaluronic acid

Back 3

cartilage, synovial fluid, vitreous humor of the eye

Front 4

Medical uses of hyaluronic acid

Back 4

Used in eye surgery and treatment of osteoarthritic pain

Front 5

Most abundant glycosaminoglycan in the human body

Back 5

Chondroitin sulfates

Front 6

Increased accumulation of __________ in mitral valves is associated with thickening and abnormal displacement of the valve into the left atrium of the heart (mitral valve prolapse).

Back 6

dermatan sulfate

Front 7

The only glycosaminoglycan that does not contain an acidic sugar

Back 7

Keratan sulfates

Front 8

Glycosaminoglycan used as a anticoagulant in medicine

Back 8

Heparin

Front 9

The linkage region to which a GAG is attached to a protein to form a proteoglycan.

Back 9

Hydroxyl of serine or amide of asparagine

Front 10

Name for cartilage proteoglycan

Back 10

Aggrecan

Front 11

A group of lysosomal storage diseases.

Back 11

Mucopolysaccharidoses

Front 12

Functions of glycoproteins

Back 12

Cell surface recognition (including binding sites for pathogens)
Blood group antigens
Extracellular matrix molecules
Mucins
Plasma proteins

Front 13

Where is the oligosaccharide chain built during the synthesis of an O-linked glycoprotein?

Back 13

Golgi

Front 14

The only glucose transport protein that is insulin independent

Back 14

GLUT-2

Front 15

Glucose transport protein in muscle and adipose cells

Back 15

GLUT-4

Front 16

Glucose transport protein in hepatic cells

Back 16

GLUT-2

Front 17

Glucose transport protein in the brain

Back 17

GLUT-1 and GLUT-3

Front 18

Phosphorylation of glucose into G-6-P is catalyzed by:

Back 18

Hexokinase

Front 19

Enzyme the phosphorylates glucose in the liver. Has a high Km.

Back 19

Glucokinase

Front 20

The isomerisation of G-6-P into F-6-P is catalyzed by what enzyme?

Back 20

Phosphoglucose isomerase

Front 21

The phosphorylation of F-6-P to F-1,6-BP is catalyzed by what enzyme?

Back 21

phosphofructokinase-1 (PFK-1)

Front 22

Irreversible reaction in glycolysis. The "committed" step.

Back 22

Phosphorylation of F6P

Front 23

Enzyme that catalyzes the cleavage of F-1,6-BP

Back 23

Aldolase

Front 24

This compound inhibits enolase and results in a decrease in ATP synthesis

Back 24

Fluoride

Front 25

Inhibits glyceraldehyde 3-P dehydrogenase

Back 25

Arsenate

Front 26

Possible fates of pyruvate

Back 26

Alanine (carrier of amino groups from muscle to liver)
Oxaloacetate (ATP used)
Lactate (NADH used)
Acetyl-CoA/CO2 (In presence of O2)

Front 27

Isoenzymes of Lactate dehydrogenase are used in detecting the following diseases: (4)

Back 27

Cardiac (myocardial and pulmonary infarctions)
Hepatic (hepatitis and cirrhosis)
Skeletal muscle (hypoxia and muscle trauma)
Neoplastic disorders: leukemias and large tumors

Front 28

Pyruvate dehydrogenase requires what 5 coenzymes in order to function?

Back 28

Thiamine pyrophosphate
Lipoic acid
CoA
FAD
NAD+

Front 29

Enzyme responsible for the isomeration of dihydroxyacetone phosphate (DHAP) and glyceraldehyde 3-phosphate (GAP).

Back 29

Triose phosphate isomerase

Front 30

Two possible way to ways to rexoidize NADH -> NAD+

Back 30

ETC in the presence of oxygen

Pyruvate + NADH <-> Lactate + NAD+

Front 31

Possible outcomes of pyruvate metabolism

Back 31

Alanine (carrier of amino groups from muscle to liver)

Oxaloacetate (used to replenish TCA cycle or in gluconeogenesis)

Lactate

Acetyl-CoA (Used in TCA cycle or for fatty acid synthesis)

Front 32

End products of glycolysis

Back 32

2 ATP
2 NADH
2 Pyruvate

Front 33

Low blood pH (high lactate) inhibits which glycolytic enzyme?

Back 33

Phosphofructokinase

Front 34

High levels of ATP inhibit which 2 glycolytic enzymes?

Back 34

Phosphofructokinase
Pyruvate kinase

Front 35

Sources of Acetyl-CoA

Back 35

Plamitate (Fatty acid)
Acetoacetate (ketone body)
Pyruvate
Ethanol

Front 36

The conversion of GTP and ATP is catalyzed by what enzyme?

Back 36

nucleoside diphosphate

Front 37

In the brain, this TCA intermediate is converted into the neurotransmitter GABA

Back 37

a-ketoglutarate

Front 38

During fasting, this TCA intermediate is transported into cytosol and used in gluconeogenesis.

Back 38

Malate

Front 39

This TCA intermediate is used in fatty acid synthesis

Back 39

Citrate

Front 40

This TCA intermediate is used to form heme

Back 40

succinyl CoA

Front 41

These 2 TCA intermediates can be used for amino acid synthesis

Back 41

Oxaloacetate and a-ketogluterate

Front 42

Pyruvate carboxylase is activated by _________.

Back 42

Acetyl CoA

Front 43

This enzyme forms oxaloacetate from pyruvate

Back 43

Pyruvate carboxylase

Front 44

The oxidation of one NADH yields roughly how many ATP?

Back 44

~2.5

Front 45

The oxidation of one FADH2 yields roughly how many ATP?

Back 45

~1.5

Front 46

Mitochondrial transport protein that transports ADP from cytosol and ATP to cytosol

Back 46

Adenine nucleotide translocase (ANT)

Front 47

Mitochondrial transport protein that transport Pi into mitochondria

Back 47

Phosphate transporter

Front 48

This mitochondrial transport shuttle is only active when NADH/NAD ratio is higher in cytosol than in the mitochondria.

Back 48

malatate-asparate shuttle

Front 49

In the glycerophosphate shuttle, roughly how many ATP are generated for each NADH oxidized?

Back 49

~1.5

Front 50

In the malate-aspartate shuttle, roughly how many ATP are generated for each NADH oxidized?

Back 50

~2.5

Front 51

Poision that binds to ATP synthase and blocks H+ channel. Can result in high levels of lactate in blood and urine.

Back 51

Oligomycin

Front 52

Two poisons that inhibit complex IV in ETC

Back 52

Carbon monoxide and cyanide

Front 53

Poison used as an insect control in gardens and on pets. Inhibits complex I

Back 53

Rotenone

Front 54

Poison that inhibits complex I and is used as a sedative and a hypnotic.

Back 54

Amytal

Front 55

A fungicide that inhibits complex III

Back 55

Antimycin A

Front 56

Tissues/cells that do not use fatty acids during fasting as an energy source

Back 56

Red blood cells (no mitochondria)
Adipocytes
Brain

Front 57

The process of adipose tissue being degraded into triglycerides during a fasting state is stimulated by:

Back 57

elevated glucagon/insulin ration and high epinephrine levels

Front 58

Fatty acids released from the adipose tissue are bound to _________ and delivered to target tissues

Back 58

albumin

Front 59

Degradation of fatty acids mainly occurs where?

Back 59

mitochondria

Front 60

In order to be metabolized, fatty acids have to be converted to _________.

Back 60

Fatty acyl CoA

Front 61

Fatty acyl CoA can be converted to: (3)

Back 61

Energy (most tissues, liver)
Storage - Triacylglycerols (adipocytes)
Membrane lipids

Front 62

Rate limiting enzyme for transporting long chain fatty acids into the mitochondria

Back 62

Carnitine palmitoyl transferase I (CPTI)

Front 63

Storage site for most carnitine in the human body

Back 63

Skeletal muscle

Front 64

During B oxidation of long chain fatty acids, what is generated during every cycle?

Back 64

FAD(2H), NADH, Acetyl CoA

Front 65

Number of ATP generated from one Acetyl CoA in the TCA cycle

Back 65

10

Front 66

Where does w oxidation take place?

Back 66

ER

Front 67

The main difference between peroxisomal degradiation of fatty acids and beta oxidation is:

Back 67

No FAD(2H) production in peroxisomal degradition

Front 68

The 3 ketone bodies

Back 68

Acetoacetate
B-Hydroxybutyrate
Acetone (not used physiologically)

Front 69

Liver enzyme responsible for converting glucose 6-phosphate to glucose. This enzyme is not present in muscle cells.

Back 69

Glucose 6-phosphatase

Front 70

Chain elongation of glycogen is catalyzed by what enzyme?

Back 70

glycogen synthase

Front 71

Glycogen branching enzyme

Back 71

4:6 transferase

Front 72

Regulated enzyme in glycogenolysis

Back 72

glycogen phosphorylase

Front 73

What part of the cell is glucose 6-p converted to glucose?

Back 73

ER

Front 74

In the liver, after glucose 6-p is converted to glucose, the glucose is transported into the cytosol via which transporter?

Back 74

GLUT-7

Front 75

Glucose is transported out of liver cells into circulation via which transporter?

Back 75

GLUT-2

Front 76

Positive allosteric regulator of glycogen synthesis.

Back 76

Glucose 6-Phosphate

Front 77

Allosteric regulators of glycogen degradation

Back 77

Low glucose (liver only)
High AMP (Muscle only, generated during exercise)
Low glucose 6-phosphate
Low ATP

Front 78

Glycogen degradation is activated by phosphorylation of ________

Back 78

Glycogen phosphorylase

Front 79

Glycogen synthesis is inhibited by phosphorylation of ________

Back 79

Glycogen synthase

Front 80

Epinephrine acts through what 2 receptors?

Back 80

B2-adrenergic
A1-adrenergic

Front 81

The main activator of glycogenolysis and glycolysis in exercising muscle

Back 81

AMP

Front 82

The most sensitive reflection of energy need in skeletal muscle during exercise.

Back 82

Changes in AMP levels

Front 83

The major regulated step of beta oxidation in muscle

Back 83

Carnitine-palmitoyl transferase-1 (CPT-1)

Front 84

Allosteric inhibitor of Carnitine-palmitoyl transferase-1 (CPT-1)

Back 84

Malonyl CoA

Front 85

In fasting conditions, high levels of ______ and _____ in cardiac muscle will inhibit glycolysis.

Back 85

acetyl CoA
Citrate

(PFK-1 and PDH are inhibited)

Front 86

2 Enzymes lacking in muscle that prevent gluconeogenesis

Back 86

glucose 6-phosphatase
pyruvate carboxylase

Front 87

Symptoms for lactate dehydrogenase deficiency

Back 87

Muscle cramping and myoglobinuria after intense exercise

Front 88

Sources of lactate

Back 88

RBCs
Lens and cornea
Skin
Skeletal muscle

Front 89

How much ATP is required to form a glucose molecule from lactate?

Back 89

6

Front 90

Enzyme that catalyzes Alanine -> Pyruvate

Back 90

Alanine aminotransferase

Front 91

Deaminated amino acids used in gluconeogenesis

Back 91

Alanine -> Pyruvate
Aspartate -> Oxaloacetate
Glutamate -> a-ketogluterate

Front 92

Pathway of glycerol in gluconeogenesis

Back 92

Glycerol -> Glycerol 6-phosphate -> Dihydroxyacetone phosphate

Front 93

Symptoms of biotinidase deficiency

Back 93

seizures
hypotonia
breathing problems
delayed development

If not treated:
hearing loss
vision loss
alopecia (hair loss)
ataxia
skin rashes
candidiasis

Front 94

Allosteric inhibitor of fructose-1,6-bisphosphatase

Back 94

Fructose-2,6-bisphosphate

(Product of PFK-2: F6P -> F2,6BP)

Front 95

Decrease in fructose-2,6-bisphosphate causes:

Back 95

Inhibition in glycolysis
Activation of gluconeogenesis
Activation of lipolysis

Front 96

Increase in fructose-2,6-bisphosphate causes:

Back 96

Glycogenesis
Glycolysis
Lipogenesis

Front 97

Increased acetyl-CoA in the liver causes:

Back 97

Increased gluconeogenesis
Inhibition of pyruvate dehydrogenase
Allosteric activation of pyruvate carboxylase

Front 98

Vitamin B1 (thiamine) levels are assessed byt the activity of ________________.

Back 98

Red blood cell transketolase.

Front 99

Major uses of NADPH

Back 99

Fatty acid synthesis
Cholesterol synthesis
Steroid synthesis
Nitric oxide synthesis
Deoxyribonucleotide synthesis

Front 100

Defensive utilization of NADPH

Back 100

Protection against oxidative damage (erythrocytes)

Detoxification of xenobiotics

Superoxide synthesis

Front 101

Enzyme that generates superoxide in the phagolysosome to destroy bacteria.

Back 101

NADPH Oxidase

Front 102

To synthesize glucose (gluconeogenesis), the liver can use what?

Back 102

Amino Acids
Glycerol
Lactate