Cell Bio Exam 2

protein

ATP Synthase in the inner mitochondrial and chloroplast membranes is a

ii only

High energy phosphate bonds are present in which of the following molecules?

1. Glucose

2. ATP

3. Water

given off as heat

When bonds are broken, energy that is not used by the cell to carry out cellular processes is

chloroplasts and mitochondria

In plants, ATP is synthesized in the

relocation of electrons in redox reactions

How is the energy stored in food molecules released and used to synthesize ATP?

cytoplasm

Anaerobic metabolism of glucose occurs in the

i and ii only

Activation energy consists of 2 ATP for:

1. aerobic respiration

2. anaerobic respiration

3. photosynthesis

both processes share the same oxidizing agent to accept the electrons from food during glycolysis

Which of the following statements is true about respiration and fermentation?

glycolysis

The cytoplasm (cytosol) is the site of which process?

NADH is not oxidized

Glycolysis does not continue if

substrate-level phosphorylation

In anaerobic respiration, ATP is formed through

enzymes catalyze a reaction

During each step of glycolysis

e

Which of the following processes utilizes ATP?

 

a. fermentation

 

b. photosynthesis

 

c. dehydration synthesis

 

d. glycolysis

 

e. all of the above

36

How many ATP are produced from 1 molecule of glucose by aerobic respiration?

c

The chemiosmotic gradient is established across

b

Pyruvate is converted to Acetyl-CoA

endosymbiont theory

The similarities between the mitochondria and certain prokaryotes support the

34

If 2 molecules of pyruvate are supplied to an aerobic eukaryotic cell in place of a glucose molecule, the net output of ATP after complete metabolism would be

the direct energy source driving the synthesis of ATP during oxidative phosphorylation

The H⁺ gradient established on the opposite sides of the mitochondrial matrix is

Oxygen

Which of the following is the final acceptor of electrons in the electron transport chain?

Connexin

Which integral membrane protein organizes into channels that connect cells via gap junctions

Proteoglycan

Which typically consists of a core portein attached to glycosaminoglycans (GAGs)

Active, able to bind ligand

When an integrin’s extracelluylar structure is upright and extended it is:

intermediate filaments

Filaments connected to the dense plaque underlying the membrane in a desmosome are called:

cadherin, actin

Adherens junctions are mediated by the extracellular protein ______ and attach to _____ inside of the cell

intermediate filaments

Which cytoskeletal element is described as tough, stable, fibers composed of a variety of related proteins like keratin

hemidesmosome

what is the specialized ahesive structure that anchors cells to a basement membrane

integrins

this class of integral membrane proteins (involed in ECM attachment) are composed of variable alpha and beta subunits

4

how many carbons from 1 original glycose molecule enter into the TCA (krebs) cycle in the presence of oxygen

ATP synthase

which enzyme couples the potential energy of an electrochemical gradient to the formation of ATP

kinase

What type of enzyme phosphorylate other molecules

Inner membrane space, thylakoid lumen

electron transport causes accumulation of H+ in which specific spaces of the mitochondria and chloroplast (respectively)

Glyceraldhyde-3-phosphate

what is the direct product of 1 turn of the Calvin cycle (light dependent reactions)

acetyl-CoA

which molecule enters into the TCA

pumping H+ agains their electrochemical gradient

as electrons move along the ETC this is accompanied by

NAD+

NAD+ and NADH are important electron carriers. Which version of this molecule is oxdixed?

more ordered

If the entropy of a system is decreased, this suggests" the system becomes

pyruvate

what chemical intermediate is the product of glycolysis

production of NAD+

what is the net result of fermentation

mitochondrial inner membrane

where in the cell do reactions of the respiratory chain (ETC) take place

atmosphere

where do plants get the CO2 needed to build carbohydrates

PDH and TCA

the CO2 we exhale comes from

lower activation energy

how do enzymes work

released free energy

hydrolysis of ATP can be described as a reaction that (G)

couple the reaction with another that has a larger negative G

how do cells perform a reaction with a positive G

endergonic

a positive G indicated that the reaction is

catalyze the removal of phosphate residues from proteins

Protein phosphatases

proteasome

multisubunit protease complex that degrades proteins marked for destruction.

GTP

Monomeric G proteins, such as Ras and several elongation factors, are usually in the active state when a molecule of _______ is bound to them.

protein kinases

Proteins are often regulated by phosphorylation, which is catalyzed by enzymes called

Steroid hormones

Which of the following regulates genes by binding directly to transcription factor proteins?

c

Which of the following is an example of endocrine signaling?

 

a. Epinephrine release by motor neurons at the neuromuscular junction and binding to receptors on adjacent skeletal muscle cells

 

b. Antigen stimulation of T lymphocytes, leading to the stimulation and synthesis of a growth factor that drives their own proliferation

 

c. Insulin release by β cells in the pancreas, mediating an effect of glucose uptake by muscle cells

 

d. None of the above

b

Which statement regarding heterotrimeric G proteins in a resting state is true?

 

a. GDP is bound to the β subunit in a complex with both the α and γ subunits.

 

b. GDP is bound to the α subunit in a complex with both the β and γ subunits.

 

c. GTP is bound to the α subunit in a complex with both the β and γ subunits.

 

d. The proteins are in a complex with G protein-coupled receptors.

e

a. G protein-coupled receptors are important molecules involved in signal transduction. Which statement about G protein-coupled receptors is true?

 

b. They are activated only by steroid hormones.

 

c. They bind only guanine nucleotides.

 

d. They bind both adenine and guanine nucleotides.

 

e. They generally contain seven membrane-spanning α helices.

adenylyl cyclase

Cyclic AMP (cAMP) is synthesized from ATP by the action of

b

Receptor tyrosine kinases represent critical molecules involved in growth and differentiation though phosphorylation of target substrates on tyrosine residues. Which structural feature is not common among all receptor tyrosine kinases?

 

a. An N-terminal extracellular ligand-binding domain

 

b. A single polypeptide

 

c. A cytosolic C-terminal domain with tyrosine kinase activity

 

d. A single transmembrane α helix

d

Which of the following is not a commonly observed consequence of the binding of a signaling molecule to its cell surface receptor?

 

a. Receptor dimerization

 

b. Receptor phosphorylation

 

c. Conformational changes in the receptor

 

d. Increased synthesis of the receptor

heterotrimeric G protein that separates into α and βγ subunits

The G protein that activates adenylyl cyclase is a

active α subunts

A mutation that causes a G-protein to lose its ability to hydrolyze bound GTP would be expected to have constitutively

eliminate activation of protein X

Protein X is activated by protein kinase A. A mutation in protein X that replaces the protein's only serine residue with an arginine residue would be expected to

phosphorylation by protein kinase A in the nucleus.

CREB is activated by

mitogen-activated

MAP kinase is an abbreviation for _______ protein kinase.

phosphatidylinositide (PI) 3-kinase

The second messenger, phosphatidylinositol 3,4,5-trisphosphate (PIP₃) is generated by the action of the enzyme _______ on phosphatidylinositol 4,5-bisphosphate (PIP₂).

receptor dimerization

What is the immediate result once most receptor protein-tyrosine kinases bind to their ligand?

a

Upon their activation, receptor tyrosine kinases phosphorylate cytoplasmic substrate proteins, thereby altering ________

a. All of the choices are correct

b. their actiity

 

c. their localization

 

d. their ability to interact with other proteins within the cell

ligand-gated ion channel

Which type of receptor is directly involved in a change of distribution of ions on opposite sides of the membrane?

They have 7 transmembrane α-helices

Why are G-protein coupled receptors often known as 7TM receptors?

isoforms

Receptors for a given ligand can exist in several different versions called _______

a

Which of the following events takes place during cell signaling?

a. all of the choices are correct

b. a response to stimuli

 

c. biochemical changes

 

d. intercellular communication