BIOC 385 Final Exam

Compared with Gram-negative bacteria, Gram-positive bacteria have a

thicker peptidoglycan layer.

Which tissue types are affected the most by inherited mitochondrial disorders?

those tissues with the highest levels of mitochondria and high levels of activity

In the breakdown of glycogen by glycogen phosphorylase, the immediate predominant product is

glucose-1-phosphate.

Which enzyme in the pentose phosphate pathway is regulated to control flux through the pathway?

glucose-6-phosphate dehydrogenase

Which enzyme uses cellular NADPH to regenerate reduced glutathione?

glutathione reductase

In comparison with gangliosides, the structure of phosphatidylcholine contains a

glycerol moiety.

Snake venom often secretes phospholipase A2 enzymes, which cleave

glycerophospholipids.

Which pathway is opposite to gluconeogenesis?

glycolysis pathway

What is the cellular location of the plant glyoxylate cycle?

glyoxysome

What active site cofactor is found in the electron transport system protein called cytochrome c?

heme

Which pair of opposite enzymes in the glycolysis and gluconeogenesis pathway are not allosterically regulated but rather regulated by compartmentalization?

hexokinase/glucose-6-phosphatase

The gluconeogenesis reaction shown below is missing some reactants and products. What class of enzyme catalyzes this reaction?

hydrolase

The activation of glycogen phosphorylase will lead to a(n) __________ in blood glucose concentrations and is stimulated by the hormone __________.

increase; glucagon

Brown adipose tissue is brown in color because of

increased numbers of mitochondria.

Which enzyme does penicillin target in bacteria?

transpeptidase

Under what condition(s) do the wasteful side reaction of O2 with rubisco become significant?

increased temperature and intense light

Chylomicrons are produced in

intestinal epithelial cells.

The B-oxidation of mono- and polyunsaturated fatty acids

involves isomerization and in some cases reduction of the double bonds before the continuation of b-oxidation.

Unlike plant cells, animal cells lack the glyoxylate enzymes

isocitrate lyase and malate synthase.

Which eicosanoid acts as an inflammatory mediator that also regulates smooth muscle contraction?

leukotriene

For photosynthesis, sunlight energy drives electron transfer. Where are the electrons ejected from when light is absorbed?

light-harvesting pigments in PSI and PSII

Gram-negative bacteria contain which potent inflammatory agent in animals?

lipopolysaccharide

The outer membrane of Gram-negative bacteria contains glycolipids called

lipopolysaccharides

The glyoxylate cycle reaction shown below is catalyzed by which enzyme class?

lyase

Which technique can identify N-linked glycans in a mixed sample?

mass spectrometry

The photosynthetic Z scheme describes the

movement of electrons driven by the absorption of light energy.

What type of antibody or antibodies is/are found in the plasma of a person with type AB blood?

neither anti-A or anti-B

The conversion of pyruvate to phosphoenolpyruvate (PEP) in gluconeogenesis

occurs in two steps and is catalyzed by the enzymes pyruvate carboxylase and phosphoenolpyruvate carboxykinase.

Which simple sugar major group ranges in size from 3 to 20 branched and unbranched sugar residues?

oligosaccharides

Protons are pumped by mitochondria during active electron transport

outside the inner mitochondrial membrane.

What group in photosystem II (PSII) directly reacts with H2O during its light-driven oxidation?

oxygen evolving center

What triggers the Cori cycle?

oxygen-limited working muscle cells

If the ratio of NADP+ to NADPH were high, the

pentose phosphate pathway oxidative phase would be activated.

The inner layer of the plasma membrane of human erythrocytes contains mostly __________ lipids.

phosphatidylserine

Which of the following is an electron transfer molecule in photosynthesis light reactions?

plastoquinone

A fatty acid that has more than one double bond is referred to as

polyunsaturated.

Which eicosanoid controls platelet formation?

prostacyclin

What is the name of the enzyme that removes phosphate groups from the regulated glycogen metabolism enzymes to reverse their activity?

protein phosphatase 1

The structure of the electron transport system protein called cytochrome c is highly conserved in nature because the

protein plays an important role in the electron transport system and in other critical cellular pathways such as apoptosis.

As electrons from NADH pass through the electron transport system,

protons are pumped across the mitochondrial membrane to create a pH gradient.

The third stage of the three-stage Calvin cycle

regenerates a C5 sugar for the Calvin cycle to continue.

The following picture is an example of what phenomenon?

resonance energy transfer

Which of the following amino alcohols act as the functional group attached to a phosphate in a glycerophospholipid?

serine

The addition of phosphocholine to ceramides generates

sphingomyelin

Which membrane lipids are derivatives of long chain amino alcohols synthesized from palmitate and serine?

sphingosines

Which glucose homopolymer is generated during daylight hours in plants?

starch

What is the name of the plant leaf openings that open during the night and close during the day in CAM plants?

stomata

Which part of the native ATP synthase enzyme is stationary and does NOT rotate during ATP synthesis?

the catalytic headpiece

Which of the following oligosaccharides are found in high abundance in some types of vegetables and have been known to cause intestinal distress?

varbascose

Both methicillin and penicillin are inactive when exposed to

variant transpeptidase.

The O2 generated from photosynthesis is derived from

water molecules that directly reduce PSII*.

The following fatty acid __________ be metabolized by __________.

will; being run through the B-oxidation pathway until the double bond is isomerized for the pathway to continue

Which type of fatty acid plays important roles in cell recognition such as in ABO blood groups?

gangliosides

How many more passes through B-oxidation does the saturated fat stearic acid (18:0) require, compared with the monounsaturated fat oleic acid (18:1)?

0

How many moles of NADH are required in gluconeogenesis to convert 2 moles of pyruvate molecules into 1 mole of glucose?

2

In C3 plants CO2 is first incorporated into __________, whereas in C4 and CAM plants the CO2 is first incorporated into __________.

3-phosphoglycerate; oxaloacetate

What enzyme uses the proton motive force for its driving force?

ATP Synthase

Which statement is true of the mitochondrial electron transport system?

All the electrons in the chain end up on O2 to produce water.

The image below shows a(n) __________ glycosidic bond.

B-1,4-

What molecules are missing from boxes in the gluconeogenesis reaction shown below?

H2O; Pi

Which of the following is true of the glyoxylate cycle?

It allows plants to produce glucose from fats and two-carbon molecules like acetate.

Which one of the following statements about the glycerol phosphate shuttle is true?

It involves the transfer of electrons from cytoplasmic NADH to dihydroxyacetone phosphate (DHAP) to yield glycerol phosphate.

The first enzyme in the electron transport system is referred to as complex I, otherwise known as

NADH-ubiquinone oxidoreductase.

What molecule activates the pentose phosphate pathway?

NADP+

Because of antibody recognition, which of the following blood types can donate to a person with type O blood?

O

What is the blood type of a person who fails to express either the GTA or GTB glycosyltransferases?

O

25-Hydroxyvitamin D3 is converted to 1,25-hydroxyvitamin D3 by

P450C1 hydroxylase.

Which is NOT a correct analogy between the photosynthetic PQ cycle and the mitochondrial electron transport chain Q cycle?

Photosystem I is analogous to Complex I.

What would happen if mitochondria were treated with a proton gradient uncoupler, such as 2,4-dinitrophenol?

Protons would be pumped by the mitochondrial electron transport chain, although no ATP would be synthesized.

Identify the polyunsaturated fatty acid.

The option with two double bonds

What is the driving force for ATP synthesis by the ATP synthase enzyme?

The pH gradient across the inner mitochondrial membrane.

What is the effect of oligomycin, an ATP synthase inhibitor, on the mitochondrial oxidative phosphorylation pathway?

The proton gradient is formed, but no ATP synthesis can occur.

Which of the following amino alcohols act as the functional group attached to a phosphate in a glycerophospholipid?

ethanolamine

The structure of raffinose, stachyose, and verbascose differ in the number of __________ units attached to a __________.

galactose; sucrose

A patient is found to have a mutated enzyme that results in fewer branch points in glycogen. Which one of the following would best characterize the way in which the patient's glycogen is altered relative to normal glycogen?

a decreased ratio of nonreducing to reducing ends

To detect lectins on the surface of pathogenic and nonpathogenic bacteria, __________ would be used.

a glycan array

The catalytic headpiece of the ATP synthase enzyme is primarily composed of which subunits?

a hexameric a3B3 ring

Resonance energy transfer from one chlorophyll in the photosystems results in

a neighboring chlorophyll in an excited state.

Which of the following metabolites is NOT a gluconeogenesis substrate in humans?

acetate

Which molecule allosterically activates pyruvate carboxylase?

acetyl-CoA

In the reaction catalyzed by pyruvate carboxylase (the first reaction in gluconeogenesis), CO2 is

activated by ATP energy.

The five-step mechanism of ribulose bisphosphate carboxylase (rubisco)

adds a CO2 molecule to a C5 ribulose sugar, yielding an unstable C6 molecule that cleaves into two C3 molecules.

A patient is having problems regulating blood pressure and has poor kidney function. Which steroid could be responsible for this?

aldosterone

What type of antibody or antibodies is/are found in the plasma of a person with type A blood?

anti-B

ATP synthesis occurs

at the ATP synthase complex after ADP and Pi are transported into the mitochondria.

During the process of saponification, fatty acid molecules are released from triacylglycerols by treatment(s) with a strong

base and heat.

Which of the following is NOT required to activate rubisco?

binding of the biotin cofactor

Which cell type in C4 plants is isolated from O2 exposure as they perform Calvin cycle reactions?

bundle sheath cells

Which functional group on penicillin forms a complex with transpeptidase of the bacterial wall?

carbonyl

Which glycan is a major component of plant cell walls?

cellulose

The total content of __________ is approximately the same in both the inner and outer layer of the plasma membrane of human erythrocytes.

cholesterol

Which is NOT involved in the transfer of reducing equivalents from succinate to molecular oxygen (O2)?

complex I

Which of the following is NOT a role played by the pentose phosphate pathway?

converting pyruvate into TCA cycle intermediates

The gluconeogenesis pathway

converts two 3C sugars into a 6C sugar.

One of the functions of the lipid rafts is to

coordinate cell signaling.

Which complex in the photosynthetic electron transport chain pumps protons as electrons pass through it?

cytochrome b6f

Which enzyme in the photosynthetic Z scheme catalyzes the PQ cycle, which is analogous to Complex III and the Q cycle in the mitochondrial electron transport chain?

cytochrome b6f

Tay-Sachs disease, Fabry disease, and Niemann-Pick disease are all symptomatic because of

defects in sphingolipid metabolism.

What class of biomolecule is glycogenin?

enzyme

Which steroid hormone is synthesized in the ovaries?

estradiol