EXAM 2 (3,4,5,6)

Where is the electron transport chain? 1. outer mitochondrial membrane 2. mitochondrial matrix 3. inter-membrane space of the mitochondria 4. inner mitochondrial membrane 5. cytosol

Coenzyme A is derived from which of the following vitamins? 1. vitamin C 2. vitamin A 3. pantothenic acid 4. riboflavin 5. niacin

The final product of glycolysis under aerobic conditions is pyruvate. What happens to pyruvate under aerobic conditions? 1. Pyruvate is converted to lactic acid in the cytosol. 2. Pyruvate enters the mitochondrial matrix where it is converted into acetyl CoA. 3. Pyruvate is converted to lactic acid in the mitochondrial matrix. 4. Pyruvate provides electrons to the electron transport chain. 5. Pyruvate is converted into acetyl CoA in the cytosol, and the acetyl CoA then enters the mitochondrial matrix.

According to the first law of thermodynamics, energy cannot be created or destroyed. True False

Where does glycolysis occur? 1. lysosomes 2. mitochondrial matrix 3. mitochondrial inter-membrane space 4. cytosol 5. mitochondrial inner membrane

In the presence of oxygen, the process of glycolysis produces which of the following products? 1. 1 lactate 2. 2 pyruvate 3. 2 glycerol 4. 2 lactate 5. 1 pyruvate

The sum of the thousands of chemical reactions that occur within the body is called ________. 1. hydrolysis 2. reduction 3. oxidation 4. metabolism 5. phosphorylation

Chemical reactions are only able to occur in one direction. True False

In an endergonic reaction... 1. the reaction proceeds spontaneously 2. the only product of the reaction is heat 3. the only product of the reaction is water 4. the change in energy of the reaction is positive 5. none of these are true for an endergonic reaction

Which of the following statements is true of an enzyme-catalyzed reaction that is at equilibrium? 1. the reaction is proceeding at its maximum rate 2. there is no difference between the energy level of of the reactants and the energy level of the products 3. the reaction is prevented from occurring 4. there are equivalent amounts of substrate and product present

Most enzymes are _________. 1. trace metals 2. nucleic acids 3. proteins 4. carbohydrates 5. lipids

A _________ is a type of enzyme that alters an enzyme's activity by phosphorylating it. 1. protein kinase 2. dehydrogenase 3. phosphorylase 4. synthase 5. cofactor

Of the following, which does NOT occur in the mitochondria or on the mitochondrial membrane? 1. conversion of pyruvate to lactate 2. Kreb's cycle 3. oxidative phosphorylation 4. consumption of oxygen 5. production of carbon dioxide

When oxygen is limited, the pyruvate that results from the process of glycolysis is converted into.... 1. Acetyl CoA 2. NADH 3. ATP 4. glucose 5. lactate

In regards to ATP synthesis from ADP, substrate-level phosphorylation is ________ and oxidative phosphorylation is _______. 1. aerobic; anaerobic 2. spontaneous; non-spontaneous 3. anaerobic; aerobic 4. non-spontaneous; spontaneous 5. reduction; oxidation

The enzyme ATP synthase harnesses the potential energy from _______ to generate ATP. 1. the phosphorylation of cytochromes 2. the sodium gradient across the inner mitochondrial membrane 3. the hydrogen ion gradient across the inner mitochondrial membrane 4. enzyme complex B 5. chloroplasts

Glucose is stored in the liver cells as... 1. starch 2. cellulose 3. lipids 4. glycogen 5. amino acids

Sodium permeability refers to a property of ________. 1. molecules 2. sodium 3. the cell membrane 4. organelles 5. lipid soluble molecules only

The potassium equilibrium potential is -94 mV. What does this means? 1. at -94 mV, potassium movement is opposed exactly by sodium movement 2. at -94 mV, the chemical force for potassium movement is zero 3. at -94 mV, the electrical force for potassium movement is zero 4. at -94 mV, the chemical force for potassium movement is opposed exactly by the electrical force 5. at the resting membrane potential of neurons, potassium is at equilibrium

Comparing intracellular to extracellular fluid, the intracellular fluid has a ________ charge relative to the outside of a cell due to the presence of more ________ in that solution. 1. negative : anions 2. positive : cations 3. neutral : cations 4. negative : cations 5. positive : anions

A membrane permeable to water separates a chamber into two compartments: A and B. Compartment A contains a 10 mM solution of non-permeating solute, whereas compartment B contains a 40 mM solution of non-permeating solute. Which of the following statements is true? 1. Solute will move from side B to A, and water will move from side A to B. 2. Solute will move from side A to B, and water will move from side B to A. 3. Water will move from side B to A, but solute will not move. 4. Both water and solute will move from side B to A. 5. Water will move from side A to B, but solute will not move.

Which of the following cells would have a greater electrical attraction for sodium ions to enter the cell? 1. cell with membrane potential = +20 mV 2. cell with membrane potential = -90 mV 3. cell with membrane potential = -50 mV 4. cell with membrane potential = 0 mV 5. cell with membrane potential = -70 mV

Which of the following best describes the potassium equilibrium potential? 1. +60 mV 2. -70 mV 3. -94 mV 4. +94 mV 5. -60 mV

If a person sprays air freshener in one room, the fragrance will eventually reach your nose even in the absence of air currents. Which of the following best describes this process? 1. Facilitated diffusion 2. Simple diffusion 3. Mediated transport 4. Flux

When more than one ion species (i.e., Na+ and K+) is present on both sides of the membrane, the chemical driving force acting on Na+ will include ________. 1. sodium only 2. the most concentrated ion only 3. all ions present 4. all positively charged ions 5. all negatively charged ions

The chemical force for which of the following ions is directed into the cell? 1. calcium only 2. both potassium and sodium 3. potassium only 4. both sodium and calcium 5. sodium only

A cell is placed into a solution that has the same osmolarity. However, one of the solutes in the solution is able to move across the membrane (the cell does not contain this solute). After a period of time, the solution into which the cell was placed would become ________. 1. hyperosmotic 2. iso-osmotic 3. hypotonic 4. isotonic 5. hypertonic

Vesicles formed during phagocytosis or endocytosis often fuse with the membrane of which of the following organelles? 1. rough endoplasmic reticulum 2. smooth endoplasmic reticulum 3. mitochondria 4. lysosome 5. peroxisome

Epithelial cells are polarized with different structures on either side of the cell. The portion of the membrane that faces the lumen is called the ________ membrane. 1. ablumenal 2. transport 3. basement 4. basolateral 5. apical

Secretory vesicles are a part of what transport mechanism? 1. osmosis 2. receptor-mediated endocytosis 3. exocytosis 4. phagocytosis 5. pinocytosis

White blood cells are an important component of our immune system. One thing they do is consume and destroy bacteria by extending their plasma membrane around the bacterium and bringing it inside the cell in a vesicle. By what process do they engulf the bacterium? 1. pinocytosis 2. phagocytosis 3. exocytosis 4. receptor-mediated endocytosis 5. transcytosis

Suppose that an anion has an equilibrium potential of -45 mV and is present in greater concentrations outside of the cell than inside the cell. At the resting membrane potential of -70 mV... 1. both the chemical and electrical forces are directed out of the cell 2. both the chemical and electrical forces are directed into the cell 3. the electrical force is directed out of the cell 4. the electrical force is directed out of the cell and the chemical force is directed into the cell 5. none of these are correct

primary active transport, secondary active transport, and facilitated diffusion share all of the following characteristics Except.... 1. they all require energy 2. they all require a protein 3. they are all specific transport mechanisms for a particular solute 4. an increase in the number of transport molecules in the plasma membrane will increase transport 5. all of these are characteristics of primary active transport, secondary active transport, and facilitated diffusion

the osmolarity of a solution contanin 0.1 M glucose and 0.1 M NaCl is.... 1. 100 mOsm 2. 200 mOsm 3. 300 mOsm 4. 400 mOsm 5. Cannot be determined

active transport of a solute across epithelium is usually followed by... 1. water movement in the opposite direction 2. water movement in the same direction 3. calcium movement in the same direction 4. calcium movement in the opposite direction 5. none of these is correct

The main difference between primary and secondary active transport is... 1. the form of energy used to move molecules across the membrane 2. the binding sites' locations 3. the direction in which molecules are being moved across the membrane 4. one requires energy by the other doesn't 5. there is no difference between primary and secondary active transport

The _________ reflects the unequal distribution of negative and positive ions across a cell's plasma a membrane 1. chemical gradient 2. extracellular potential 3. membrane potential 4. chemical driving force 5. electrochemical driving force

Very lipid-soluble molecules can cross cell membranes.... 1.with the help of protein channels 2. only with the addition of energy from ATP 3. by crossing the lipid bilayer directly 4. only with the help of protein channels and the addition of energy from ATP 5. through aquaporins

In ________, white blood cells engulf bacteria in their plasma membranes, pinch off a vesicle, and bring the bacteria into the cell. 1. phagocytosis 2.receptor-mediated endocytosis 3.pinocytosis 4.exocytosis 5. unicytosis

consider a molecule that can move across a membrane via passive transport. The direction of the molecule's movement is determined by the molecule's tendency to move... 1. out of the cell 2. into the cell 3. from higher to lower energy 4. from lower to higher energy 5. the question errs. There is no general tendency

Suppose that a semipermeable membrane (which is permeable to water) separates a chamber into two compartments: X and Y. Compartment X contains 20 mM solution of solutes that won't permeate the membrane, and compartment Y contains 50 mM solution of the same solute. This solute will _______, and water will ________. 1. mover from side X to side Y; move from side Y to side X 2. move from side Y to side X; move from side X to side Y 3. move from side X to side Y; not move 4. not move; move from side X to side Y 5. not move; move from side Y to side X

What organelle packages peptide/protein messengers into secretory vesicles? 1. rough endoplasmic reticulum 2. smooth endoplasmic reticulum 3. Golgi apparatus 4. nucleus 5. lysosomes

In its active form, a G protein has a GDP bound to its alpha unit. True False

Receptors for lipophilic chemical messengers are only located on the surface of a cell's membrane. True False

Cells that secrete dopamine must contain which enzymes? 1. dopamine β-hydroxylase and dopa decarboxylase only 2. tyrosine β-hydroxylase 3. tyrosine β-hydroxylase and dopa decarboxylase 4. dopamine β-hydroxylase only 5. dopa decarboxylase only

Direct communication between cells in contact with one another is accomplished through ________. 1. ligands 2. endocrine hormones 3. gap junctions 4. receptors 5. paracrine chemical messengers

Lipophilic chemical messengers are poorly soluble in water. However, many of these lipophilic messengers are transported throughout the body. Their transport in blood (water) is facilitated by ________. 1. red blood cells 2. lipoproteins 3. chylomicrons 4. carrier proteins 5. white blood cells

Chronic exposure to a ligand (messenger) ________ the receptor population for that chemical messenger on the target cell. 1. upregulates 2. decreases the affinity of 3. changes the conformation of 4. downregulates 5. decreases the specificity of

Slow gated channels are identified as such because, once the receptor is bound by the ligand, the receptor must first activate a(n) ________ prior to the channel opening or closing. 1. G protein 2. RNA polymerase 3. ion channel 4. hormone response element 5. enzyme

Differences in the rate of activity between fast and slow ligand-gated channels is caused by ________. 1.ligands gating both channels to the closed state 2. ligand selectivity 3. ligand affinity 4. G protein activity gating the fast channel 5. G protein activity gating the slow channel

Of the following, which is hydrophobic (i.e., lipophilic) and therefore able to cross cell membranes? 1. amino acids 2. amines (excluding thyroid hormone) 3. peptides 4. proteins 5. eicosanoids

Lipophobic messengers are stored in _________ and release ________ in response to a stimulus. 1. the mitochondria; by exocytosis 2. vesicles; by simple diffusion 3. vesicles; by exocytosis 4. the mitochondria; by simple diffusion 5. none of these is correct

All of the following can be second messengers EXCEPT... 1. calcium 2. inositol triphosphate 3. cAMP 4. The question errs. None of these can be second messengers. 5. The question errs. All of theses can be second messengers.

A cell's response to a hydrophilic ligand will be impacted by all of the following EXCEPT.... 1. the ligand's concentration 2. the number of receptors 3. the affinity of the receptor for the ligand 4. the lipid solubility of the ligand 5. all of these will impact the cell's response to a hydrophilic ligand

A steroid is capable of diffusing across a cell membrane... 1. only once it has been packaged in a vesicle 2. only once it has gone through post-translational processing 3. only once it binds to the mitochondrial matrix 4. only once it enters the mitochondrial matrix 5. immediately after it is synthesized

What kind of signaling involves a chemical that bind to the receptors on the same cell that secreted it? 1. paracrine signaling 2. autocrine signaling 3. hexocrine signaling 4. endocrine signaling 5. neurotransmission

Which class of chemical messengers acts ONLY as neurotransmitters and not as hormones or paracrines? 1. Amino Acids 2. Steroids 3. Eicosanoids 4. Amines 5. Peptides / Proteins

Slow-gated channels are called "slow because they only open once a ligand binds to the receptor and a ___________ is activated. 1. G-protein 2. lipophilic hydrolytic amine 3. enzyme 4. transposable element 5. hormone response element

The transportation of lipophilic chemical messengers (which are insoluble in water) in the blood is achieved with the help of..... 1. chylomicrons 2. lipoproteins 3. red blood cells 4. carrier proteins 5. white blood cells

The cell's response to a ____________ messenger usually takes a long time to occur because it requires transcription and translation to occur before the synthesis of a functional protein. 1. lipophobic 2. lipophilic 3. amino acid 4. protein 5. peptide

Which of the following is considered a secondary endocrine organ? 1. The thymus 2. The liver 3. The thyroid 4. The pineal gland

Neural signals from stress initiate a cascade of events that culminates in the secretion of which of the following hormones? 1. Chorionic gonadropin 2. Glucagon 3. Cortisol 4. Insulin

A person has a tumor in the hypothalamus causing an excess in TRH secretion. Which of the following correctly describes changes in plasma levels of hormones? 1. increased TRH, increased TSH, and decreased thyroid hormones 2. increased TRH, decreased TSH, and decreased thyroid hormones 3. decreased TRH, decreased TSH, and decreased thyroid hormones 4. decreased TRH, decreased TSH, and increased thyroid hormones 5. increased TRH, increased TSH, and increased thyroid hormones

The combination of Tylenol with a drug called codeine provides more relief than either drug can provide alone. This is known as___________. 1. antagonism 2. permissiveness 3. synergism 4. agonism

Hormones transported in blood bound to proteins are metabolized more slowly than those traveling dissolved in plasma. True False

Which of the following is a correct example of long-loop negative feedback? Which of the following is a correct example of long-loop negative feedback? 1. GH stimulates the release of GHIH. 2. TSH stimulates the release of TRH. 3. FSH inhibits the release of GnRH. 4. TSH inhibits the release of TRH. 5. Glucocorticoids inhibit the release of CRH.

Which of the following hormones is NOT secreted by the endocrine region of the pancreas? 1. pancreatic polypeptide 2. insulin 3. glucagon 4. glucocorticoids 5. somatostatin

What layer of the adrenal cortex secretes mineralocorticoids? 1. both zonae reticularis and glomerulosa 2. zona glomerulosa only 3. zona fasciculata only 4. zona reticularis only 5.both zonae reticularis and fasciculata

Which of the following stimulates the secreting of hormones from the anterior pituitary? 1. Stimulating hormones released from the hypothalamus 2. Oxytocin released from the hypothalamus 3. Stimulating hormones released from the posterior pituitary 4. Releasing hormones from the hypothalamus 5. Oxytocin released from the pineal gland

All of the following are released from the adrenal gland except... 1. aldosterone 2. cortisol 3. epinephrine 4. adrenocorticotropic hormone 5. The question errs. All of these are released from the adrenal gland

When two hormones act in opposition to one another, the response is said to be ___________. 1. permissive 2. synergistic 3. additive 4. agonistic 5. antagonistic

What do calcitonin and parathyroid hormone have in common? 1. They are both produced by the hypothalamus 2. they are both produced by the anterior pituitary 3. they are both used in the adrenal gland 4. they are both stored in ducts 5. they both regulate blood calcium levels

One's circadian rhythm is established, in part, by.... 1. the release of prolactin from the pineal gland 2. the release of melatonin from the posterior pituitary 3. the release of melatonin from the pineal gland 4. the release of prolactin from the posterior pituitary 5. the release of GnRH from the anterior pituitary

The posterior lobe of the pituitary gland is also called the _________. 1. adenohypophysis 2. neurohypophysis 3. cranium 4. pineum 5. paraventricular nucleus

In the pancreas, the alpha cells secrete ________ & beta cells secrete __________. 1. glucagon; insulin 2. insulin; glucagon 3. calcitonin; glucagon 4. glucagon; calcitonin 5. pancreatic polypeptide; vasopressin

When two hormones produce a response equal to the sum of their individual responses, the response is said to be _______. 1. permissive 2. antagonized 3. additive 4. synergistic 5. agonistic

Cateholamines are __________, so their receptors are located _________. 1. water-soluble; in the target cell's nucleus 2. water-insoluble; in the plasma membrane 3. water-insoluble; in the target cell's nucleus 4. water-soluble; in the plasma membrane 5. The question errs. Such generalization cannot be made.

Which of the following does the thyroid gland secrete? 1. Thyroid hormones only 2. calcitonin only 3. vasopressin only 4. Thyroid hormones and calcitonin 5. the question errs. The thyroid gland does not secrete any of these

A primary active transport process is one in which __________. 1. molecules move across the plasma membrane without an input of energy 2. molecules move through transport proteins that have been activated by ATP 3. the plasma membrane folds inward to form a vesicle containing extracellular material 4. molecules pass directly through the phospholipid bilayer of the plasma membrane 5. an intracellular vesicle fuses with the plasma membrane and releases its contents to the extracellular fluid

Some transport processes use transport proteins in the plasma membrane, but do not require ATP. This type of transport is known as _____. 1. endocytosis 2. active transport 3. facilitated diffusion 4. exocytosis 5. simple diffusion

A vesicle fuses with the plasma membrane and releases its contents to the extracellular fluid. This statement describes _____. 1. exocytosis 2. active transport 3. facilitated diffusion 4. simple diffusion 5. endocytosis

The sodium-potassium pump uses ATP to move sodium and potassium ions across the plasma membrane. This statement describes _____. 1. exocytosis 2. secondary active transport 3. facilitated diffusion 4. simple diffusion 5. primary active transport

The majority of water molecules moving across plasma membranes by osmosis do so via a process that is most similar to ____. 1. cotransport 2. active transport 3. facilitated diffusion 4. a process that requires energy from the cell 5. simple diffusion