Final Exam - Cell Biology

Cartilage is made up of cells imbedded in an ECM mainly composed of A. Collagen and Integrins B. Collagen and fibronectin C. Proteoglycans and laminin D. Hyaluronic acid and Integrins E. Collagen and proteoglycans

e

Protein A is synthesized in ER-bound (membrane bound) ribosomes. Protein A could be a ________ protein A. Golgi complex B. ER C. Mitochondria D. Plasma membrane E. A, B and D

e

The ____ is a type of extracellular matrix that form the supporting structure on which epithelial and endothelial cells grow A. Laminin B. Fibronectin C. Hyaluronidase D. Matrix metalloprotease E. Basement membrane

e

UGGT and calnexin are proteins involved specifically in the cellular process known as ____ A. Unfolded Protein Response (UPR) B. Protein Ubiquitination C. The biosynthetic pathway D. The endomembrane system pathway E. Quality control

e

What biological process occurs by presence of selectins and immunoglobulins as a primary response to infection? A. Apoptosis B. Leukocytosis C. Meiosis D. Embryogenesis E. Inflammation

e

Complete oxidation of hydrocarbons leads to the release of ______ A. Ethanol B. Glucose C. Methane D. CO2 E. Pyruvate

either methane or co2

Trans fats are the most common type of fat naturally found in animal-derived products such as bacon and egg yolk A. True B. False

false

The specialized adhesive structure that facilitates the stable adhesion of epithelial cells to the underlying basement membrane is called

hemidesmosomes

Collagen contains large amounts of hydroxylatedamino acids. These amino acids use the OH group to form _________ between the different chains, to maintain protein stability A. Van der Waals forces B. Hydrophobic interactions C. Hydrogen bonds D. Covalent bonds

hydrogen bonds

Membrane-bound ribosomes are bound to the ________, and synthesize proteins that contain a signal sequence in the _____ A. Plasma membrane; Plasma membrane B. ER membrane; Last amino acid C. Golgi membrane; C-terminus D. Plasma membrane; Transmembrane domain E. ER membrane; N-terminus

i think e

fatty acid structure

long hydrocarbon (hydrogen and carbon) chains; usually even #

Methane is ___ reduced than saturated fats. ____ energy is obtained from oxidizing 1g of methane than from oxidizing one 1g fat. A. More; Less B. More; More C. Less; Less D. Less; More

more, less

_____ act as tracks for motor proteins, kinesin and dyenin

motor proteins

All of the following are high-energy molecules that can be used as reducing agents by a cell, except A. FADH2 B. NADPH C. NADH D. NAD E. All of them are high-energy molecules

nadph

Molecules (such as water) that have an asymmetric distribution of charges are referred to as: A. Polar B. Nonpolar C. Acids D. Bases

polar, A

The presence of the hydroxyl (OH) groups makes glucose molecules highly ______ in water

soluble

"Substance that releases protons when it is dissolved in water" better describes ___ A. Buffer B. Dye C. Hydrophilic D. Acid E. Base

acid

hyper phosphorylation of tau is associated with what disease?

alzheimers

Based on their chemical structure, oxidizing _____ will release more chemical energy A. Six carbons of glucose B. Six carbons of a saturated fat

b

Eukaryotic cells contain two different types of ribosomes: cytosolic (free) ribosomes are chemically and structurally different from ER-bound ribosomes A. True B. False

b

How is the pH of the mitochondrial matrix relative to the intermembrane space? A. The mitochondrial matrix has lower pH B. The mitochondrial matrix has higher pH

b

Unlike malignant cells, normal cells ____ grow when they are cultured on a solid substratum. The type of signaling involved in this process is an example of _____ A. Can only; Inside-out signaling B. Can only; Outside-in signaling C. Cannot; Inside-out signaling D. Cannot; Inside-out signaling

b

What could be defined as an organized network of extracellular materials found beyond the immediate vicinity of the plasma membrane? A. Intracellular matrix B. Extracellular matrix C. Extracellular material D. The matrix

b

A tissue has been briefly labeled with radiolabeled amino acids. It is then transferred to a medium containing unlabeled amino acids. This can be done several times with different tissue samples for varying periods of time. What is the entire procedure called ? A Pulse B. Chase C. Pulse-Chase D. GFP-Chase E. RACE

c

When cells from different parts of an embryo are dissociated and then intermixed, the cells initially aggregate and then sort out by associating with other cells of the same type. This recognition is mediated by ______ A. Immunoglobulins B. Integrins C. Selectins D. Cadherins E. Fibronectin

cadherins ?

What kind of proteins could act as "helpers" to alleviate stress caused by misfolded proteins? A. Chaperones B. Quality control proteins C. COPII-coat proteins D. A and B E. All of the above

chaperones and quality control (B)

Enzymatic digestion of the ECM surrounding the cartilage cells would A. Do nothing B. Get the scientist fired C. Set the scientist on fire D. Decrease their synthetic and secretory activities

d

The components of the ECM are subject to continual degradation and reconstruction. These processes are important during tissue remodeling, embryonic cell migration and wound healing, and are accomplished by a family of enzymes known as A. Extracellular proteinases B. Matrix dehydrogenases C. ECM-desaturases D. Matrix metalloproteinases E. Endotheliases

d

An ER-resident protein like disulfide isomerase contains a KDEL signal sequence on the C-terminus and a signal peptide sequence on the N-terminus A. True B. False

true

Highly saturated fatty acids tend to be solid at room temperature (Hint: think what butter is) A. True B. False

true

Laminin and Fibronectin play an important role during embryonic development, mainly by directing cell migration A. TrueB. False

true

Succinate dehydrogenase, the enzyme that catalyzes the transfer of electrons to FADH2 during the Krebs cycle, is part of Complex II in the electron transport chain A. True B. False

true

Free energy, represented by ____is defined as ____ A. G; The energy lost as heat in a chemical reaction B. E; The amount of energy transformed into entropy C. G; The amount of energy available to do work D. E; All the energy that is outside of the cell

C. G; the amount of energy available to do work

Some medications prevent heartburn by inhibiting the process of acid secretion in the stomach. One of them is Prilosec, which specifically inhibits ___ A. The H+/K+ ATPase B. The Na+/K+ ATPase C. The HCl ATPase D. The Na+/glucose cotransporter

A

Suppose you were culturing a population of bacteria at 37 °C and then lower the temperature of the culture to 15 °C . What effect do you think this might have on the fatty acid composition of the membrane? A. The level of saturation would decrease B. The level of saturation would increase

A

The C atoms in molecule A are more reduced than the C atoms in molecule B. You could expect that more energy is produced by the oxidation of ___________ A. Molecule A B. Molecule B C. Equally for both molecules

A

The voltage difference inside and outside of the membrane of a nerve cell when it is not excited, is known as A. Resting potential B. Equilibrium C. Depolarization D. Action potential E. Reuptake

A

What are the three major proteins that are involved in cell-cell adhesion/ interactions? A. Cadherins, Immunoglobulins and Selectins B. Integrins, Cadherins and Proteoglycans C. Selectins, Cadherins and Cell plate D. Intermediate filaments, Laminin and Selectins

A

Whether a person has type A, B, AB or O blood is determined by A. Specific carbohydrates attached to membrane lipids B. Specific amino acids attached to membrane lipids C. The lipids that compose the lipid bilayer of their red blood cells

A

Which one of the following organisms has the highest percentage of unsaturated fatty acids? A. Antarctic fish B. Desert snake C. Human being D. Polar bear E. Thermophilic bacterium

A

During the "pulse" of a pulse-chase experiment: A. The cell is incubated with radioactive amino acids, which are incorporated into the proteins B. The cell is incubated with unlabeled amino acids, and allowed to continue regular cellular activities

A?

The enzyme reaches saturation at ___. At this value, ________. A. Vmax; Environmental conditions are ideal for the reaction B. Vmax; All of the enzyme active sites are occupied by substrate C. Vmax; Half of the enzyme active sites are occupied by substrate D. ½ Vmax; Half of the enzyme active sites are occupied by substrate00.40.81.21.62

B. Vmax/all of the enzyme active sites are occupied by substrate

A scientist wishes to visualize movement of a protein in a living cell. Which procedure would work best? A. Pulse-chase B. Fusion of the green fluorescent protein gene to the gene encoding the protein to be tracked through the cell C. Fusion of the green fluorescent protein gene to a membrane-bound ribosome D. Pulse-chase using fluorescent antibodies

B?

All the following are true of beta-oxidation except that: A. It occurs in the mitochondria B. Fatty acids break down into two-carbon fragments C. Lipids are converted into glycogen molecules D. It requires coenzyme A, NAD+, and FADE. It yields large amounts of ATP

C

An extracellular matrix protein that binds to cell-surface integrins to promote adhesion of cells to the matrix and to provide guidance to migrating cells in developing tissues, best describes A. Collagen B. Proteoglycan C. Fibronectin D. Focal Adhesion

C

Bullous pemphigoid is an autoimmune disease that affects hemidesmosomes. You canassume that the symptoms observed related to a. Abnormal attachment of the actin filaments b. Loss of cell viability by inactivation of kinases such as FAK c. Weak attachment of the epidermis to the dermis

C

Covalent bonding is the primary bonding responsible for ____ of proteins A. Primary structure B. Secondary structure C. Tertiary structure D. Quaternary structure

C

For every ATP hydrolyzed by the Na+/K+-ATPase, also known as the Na+/K+ ____, the ratio of Na+ to K+ ions pumped is ____ A. Pump; 1:1 B. Channel; 1:1 C. Pump; 3:2 D. Channel; 3:2 E. Pump; 5:3

C

In HSP60 and HSP70, "HSP" stands for A. Heat Splicing Protease B. Human Splicing Protease C. Heat Shock Protein D. Histone Serine Phosphatase E. Human Superoxide Peroxidase

C

In a pulse-chase procedure, if the chase is longer, which statement below correctly describes the location of the radioactively labeled proteins in the cell? A. Closer to the synthesis site B. Farther from the nucleus C. Farther from the synthesis site D. Closer to the nucleus

C

In your groups: A reaction with an unfavorable (+ΔG) A. Will never occur B. Can only occur if an enzyme is added C. Can occur if it is coupled to another reaction

C

Membrane proteins are distinguished by their relationship to the lipid bilayer. All of the following are a kind of membrane protein, except: A. Peripheral proteins B. Integral proteins C. Sugar-linked proteins D. Lipid-anchored proteins

C

Review: On Monday, we were talking about the importance of protein folding. Which of the following statements is/are true about protein folding? A. Proteins always require molecular chaperones in order to fold properly B. All misfolded proteins are called prions C. Both Creutzfeldt-Jakob disease and Alzehimer's disease are protein folding diseases D. All of the above are correct

C

Saturated fats have higher melting points because ____ A. Their functional groups have different polarity than unsaturated fats B. Intermolecular interactions are weaker than between unsaturated fats C. Their shape allows them to pack closer together D. They remain liquid at room temperature

C

Substance X is a charged molecule of small molecular weight. It is found at higher concentrations outside of cells than inside. How might substance X enter cells? A. Simple diffusion through the lipid bilayer B. Active transport C. Diffusion through a channel D. Cotransport

C

The correct folding of proteins is necessary to maintain healthy cells and tissues. Unfolded proteins are responsible for neurodegenerative disorders such as Alzheimer's disease and Creutzfeldt-Jakob disease. What is the ultimate fate of these disease-causing, unfolded proteins? A. They are degraded B. They bind a different target protein C. They form protein aggregates D. They induce activity of the proteasome, inducing digestion of chaperones

C

The correct order of passage of materials produced in a biosynthetic pathway is: A. ER, Golgi complex, plasma membrane, secretory vesicle. B. ER, lysosome, secretory vesicle, plasma membrane. C. ER, Golgi complex, secretory vesicle, plasma membrane. D. Nucleus, Golgi complex, ER plasma membrane.

C

The movement of a substance from an area of high concentration to an area of lower concentration is known as ______ A. Denaturation B. Osmosis C. Diffusion D. Transport

C

The net end products of glycolysis are A. Two ATP molecules B. Four ATP and two pyruvate C. Two ATP, two NADH and two pyruvate D. Two ATP, one NADH and one pyruvateE. Two ATP, two NADH and two acetyl CoA

C

The temperature at which a lipid bilayer shifts from a fluid state to a frozen crystalline gel is called the _____ A. Temperature optimumB. Gelation temperature C. Transition temperature D. Breaking point E. Ideal temperature

C

This image shows a centrosome stained with γ-tubulin antibodies (red arrows). Which side of the microtubule is associated with the stained portion? A.The plus end, because an α-subunit will be located next to the γ-tubulin. B.The plus end, because an β-tubulin subunit will be located next to the γ-tubulin. C.The minus end, because an α-subunit will be located next to the γ-tubulin.D.The minus end, because an β-tubulin subunit will be located next to the γ-tubulin

C

What are the two types of structures that mediate intercellular (between cells) communication? A. ECM and ICAM B. Integrins and plasmodesmata C. Gap junctions and plasmodesmata D. P-selectins and gap junctions

C

In this figure, lysine is forming a(an) _______ with a negatively charged phosphate group. This is possible because lysine is a ________ amino acid A. Ionic bond; Non-polar B. Covalent bond; Non-polar C. H-bond; Non-polar D. Ionic bond; Polar charged E. Covalent bond; Polar charged

---

What happens to a glucose molecule when it loses a hydrogen atom as the result of an oxidation-reduction reaction? A. The glucose molecule is hydrolyzed B. The glucose molecule is an oxidizing agent C. The glucose molecule is oxidized D. The glucose molecule is reduced E. It acts as a base and abstracts a proton from its environment

C

What is the purpose of uncoupling proteins in mammalian brown adipose tissue? A. They give the tissue its color B. They help the tissue expand and contract when needed. C. They function as a source of heat production during exposure to cold temperatures. D. They allow the production of a larger number of ATPs per glucose. E. They allow muscles to contract more efficiently.

C

What is the source of energy for Secondary active transport? A. The energy stored in electrons B. The energy stored in an ionic gradient C. ATP hydrolysis

C

You need to increase your dietary fiber intake. To do so, you choose foods rich in polymers of glucose joined by A. α(1-4) bonds B. α(1-6) bonds C. β(1-4) bonds D. Peptide bonds

C

Assume you added another inhibitor that blocked electron transfer between cytochromes c and a (5 and 6). The this second experiment would leave A. 1 to 5 reduced; 6 oxidized B. 1 to 5 oxidized; 6 reduced C. 1 to 4 reduced; 5 to 6 oxidized D. 1 to 4 oxidized; 5 to 6 reduced

1 to 5 oxidized; 6 reduced

he Michaelis constant (KM) of an enzymatic reaction is ____ A. The maximum velocity at which substrate molecules are converted to products. B. A measure of half of the Vmax. C. A measure of the substrate concentration at one-half of Vmax. D. A measure of half of the activation energy

C

ll of the following are components of the extracellular matrix except for _____ A. Laminin B. Collagen C. Peptidoglycan D. Proteoglycan

C

Saturated fats ______ double bonds, making their fatty acid tails _____ A. Lack; Kinked B. Have multiple; Kinked C. Lack; Straight D. Have multiple; Straight E. Lack; Hydrophilic

C (lack, straight)

Assume a plasma membrane glycoprotein has a very specific and distinct arrangement of sugars, some of which need to be phosphorylated. Which of the following best describes this protein? A. This protein never passed the process of quality control B. This protein was glycosylated only in the ER C. This protein was glycosylated only in the Golgi complex D. This protein was initially glycosylated in the ER and further modified in the Golgi complex

This protein was initially glycosylated in the ER and further modified in the Golgi complex

Which of the following is NOT a part of the unfolded protein response? A. Protein synthesis in the ER is inhibited B. Transcription of genes that lower cellular stress is ceased C. Sensors are activated and chaperones like BiP are recruited to the lumen to assist in folding D. A cell death pathway can be triggered if conditions become too stressful

Transcription of genes that lower cellular stress is ceased

In summary, the E1 configuration has a higher affinity for _____, and the E2 configuration has a higher affinity for _____.

Na+ ions; K+ ions

Which of the following IS NOT a characteristic of most carbohydrates? A. Polymers of sugar molecules B. Monomers linked by glycosidic bonds C. Storage of chemical energy D. Monomers rich in polar groups and are highly water soluble E. Monomers lack charged groups and are water insoluble

E

Which of the following phenotypes would you expect to be associated with a malignant cell phenotype? A. More adhesive than normal cells B. Lower migration rates C. Higher expression of matrix metalloproteases (MMP) D. Higher expression of E-cadherins E. C and D

E

Which of the following statements is/are true about proteins? A. Secondary and tertiary structures can be stabilized by covalent bonds B. Secondary and tertiary structures can be stabilized by H-bonds C. Secondary structures can be stabilized by non-covalent bonds formed between the R groups of amino acids D. Tertiary structures can be stabilized by non-covalent bonds formed between the R groups of amino acids E. B and D are correct

E

ntegral membrane proteins should contain ______________ portions, that allows them to interact with the lipid bilayer and the aqueous environment A. Many hydrophobic amino acids B. Many hydrophilic amino acids C. Many negatively charged amino acids D. Only hydrophobic amino acids E. Portions of both hydrophobic and hydrophilic amino acids

E

the movement of glucose from the bloodstream into cells is accomplished by A. Primary active transport B. Secondary active transport C. The Na+/glucose cotransporter D. Passive diffusion across the lipid bilayer E. Facilitated diffusion

E

Lysosomal enzymes carrying a _________ are recognized by specific receptors and transported from the trans Golgi network to the lysosomes in _______ coated vesicles A. KDEL sequence; COPI B. Glucose-6-Phosphate; Clathrin C. RGD sequence: COPII D. Signal peptide; COPI E. Mannose-6-phosphate; Clathrin

E Mannose-6-phosphate; Clathrin

The process of co-translational translocation involves A. Translocation of fully synthesized proteins into the ER B. Translocation of proteins to the ER while they are still being synthesized C. Translocation of ribosomes to the membrane of the Golgi complex D. Translocation of ribosomes to the plasma membrane E. Induced transcription of extracellular proteins

E?

Lysosomal enzymes are synthesized in ______ ribosomes and are transported in ____ A. Free; COPI- coated vesicles B. Free; COPII- coated vesicles C. ER-bound; COPI- coated vesicles D. ER-bound; Clathrin-coated vesicles

ER bound, Clathrin D

endomembrane system includes

Golgi apparatus, lysosomes, vacuoles, and the endoplasmic reticulum

Why are viruses useful in the study of protein movement through the biosynthetic pathway? A. Viruses can be seen in electron microscopy, specifically colonizing the ER B. Viruses can deliver radioactive amino acids into the cell, which allows to track protein movement C. Viruses specifically colonize ER-bound ribosomes, which are secreted via the biosynthetic pathway D. Viruses force cells to synthesize and secrete large amounts of viral proteins

Viruses force cells to synthesize and secrete large amounts of viral proteins

Synthesis of all proteins starts in free ribosomes. A signal sequence in the N-terminus, signals the ribosome to temporarily halt synthesis of this peptide and relocate to the ER membrane, where synthesis of this protein continues. This process is known as A. Co-translational translocation B. Co-transcriptional translocation C. Collaborative translocation D. Ribosomal translocation

a i think

Most of the functions of a cell membrane are performed by A. Glycolipids B. Cholesterol C. Carbohydrates D. Proteins E. Phospholipids

D

Oxygen is more electronegative than Hydrogen. In a molecule of water, electrons are _____ attracted to hydrogen than to oxygen, making water a(n) _____ molecule A. More; Uncharged B. Less; Uncharged C. More; Partially charged D. Less; Partially charged E. More; Hydrophobic

D

Synthesis of ATP is driven by conformational changes in the β-subunits of the F1 head of ATP synthase that alternate between A. Open, Close and Bind B. β1, β2, β3 C. Open, Leak and Trap D. Open, Loose and Tight

D

The basal membrane normally provides an impenetrable barrier to cells, but lymphocytes and macrophages are able to cross it by digesting components of the basal membrane. This process involves the activation of a family of enzymes known as

D

The causal agent of CJD is A. An unidentified infectious agent B. A very rare DNA virus C. A retrovirus D. A prion E. An antibiotic-resistant bacteria

D

The maximal velocity (Vmax) of an enzymatic reaction refers to ________. A. The initial velocity at which the enzyme has attained its theoretical saturation point. B. The maximum number of molecules that can be converted to product per molecule of enzyme C. The maximum substrate concentration needed for optimum catalysis D. The maximum amount of substrate molecules that can bind to each molecule of enzyme

D

The refractory period occurs because: A. The neuron cannot fire again until the membrane potential returns to below threshold. B. Pre-synaptic inhibition prevents over-firing and cellular exhaustion. C. Sodium and potassium gradients across the membrane completely dissipate after every action potential D. Voltage-gated channels become inactivated for a short time following an action potential.

D

Turnover number is best defined as: A. The concentration of substrate required to saturate the enzyme B. How fast the enzyme works when it is saturated C. How much faster a reaction occurs with an enzyme compared to without an enzyme D. The maximum number of molecules of substrate converted to product by a single enzyme molecule per time

D

Which of the following is NOT a function of the plasma membrane? A. Compartmentalization B. Responding to external signals. C. Scaffold for biochemical activities. D. Preventing flow of all molecules in and out of the cell. E. Energy transduction

D

Which of the following is NOT a product of the anaerobic oxidation of pyruvate? A. Carbon dioxide B. Lactate C. Ethanol D. Acetyl CoA

D

Which of the following is NOT one of the mechanisms of enzyme catalysis by which the substrate is converted to the product? A. Changing substrate orientation B. Changing substrate reactivity C. Inducing strain in the substrate D. Controlling the rates of diffusion of substrates to enzymes

D

Which of the following is correct about the process of quality control? A. It is activated in response to the presence of abundant misfolded proteins B. Verifies that integral membrane proteins are properly embedded in the membrane. C. Occurs in the Golgi Complex D. Ensures that glycoproteins are properly folded

D

Which of the following proteins are transported by COPII-coated vesicles? A. Enzymes involved in glycosylation process in the Golgi complex B. Proteins involved in the process of quality control C. Ion channels in the plasma membrane D. A and C E. All of the above

D

Which statement best describes how cholesterol affects cell membrane fluidity? A. Cholesterol increases fluidity at high temperatures and decreases fluidity at low temperatures. B. Cholesterol increases fluidity at high temperatures and increases fluidity at low temperatures. C. Cholesterol decreases fluidity at high temperatures and decreases fluidity at low temperatures. D. Cholesterol decreases fluidity at high temperatures and increases fluidity at low temperatures

D

You are following a protein that is being transported backwards, from the Golgi complex to the ER. How do you think this protein will reach its final destination? A. It will arrive in a clathrin-coated vesicle B. It will arrive in an ER-bound ribosome C. It will arrive in a free-ribosome D. It will arrive in a COPI-coated vesicle E. It will arrive in a COPII-coated vesicle

D

LAD 1 is caused by mutations in gene that encoded by an integrin subunit (ITGB2), which is essential for_____ A. Closing neural connections during embryogenesis B. Leading migrating neural crest cells C. Adhesion of leukocytes at sites of infection D. Recognizing glycoproteins on the surface of cells

?

When a mannose (carbohydrate) is removed from a glycoprotein during quality control, the protein ____ A. Is recognized by calnexin (a chaperone), which tries to fold it again B. Is recognized by the conformation-sensing enzyme UGGT C. Cannot be recycled anymore and is degraded D. Is now properly folded and can leave the ER

?

Which of the following proteins will most likely contain a KDEL sequence? A. A selectin B. An integrin C. An enzyme involved in the process of quality control D. A protein of the Krebs cycle E. A lysosomal enzyme

?

A type of protein secondary structure, the alpha helix, is formed ____ A. Between amino acids of the same polypeptide B. Between amino acids of two different polypeptides C. Between a glycosidic bond and a peptide bond D. When two peptide bonds are broken

A

An amphipathic molecule with two hydrocarbon chains and a phosphate-containing head group, probably represents A. A phospholipid that could be part of a membrane B. A glycolipid that could be part of the nuclear envelope C. A molecule of cholesterol, important in maintaining membrane solubility

A

Considering that the pKa of an amino group of an amino acid is about 8 and of the carboxyl is 3, what would be the charge on this amino acid at pH 12? A. +1 B. 0 C. -1

A

FADH2 electrons enter _____ and NADH electrons enter ___ in the electron-transport chain A. Complex I; Complex II B. Complex I; Complex III C. Complex II; Complex III D. Complex II; Complex I

A

From a few minutes ago: What type of membrane lipids are ABO lipids? A. Sphingolipids B. Cholesterol C. Phospholipids D. Phosphoglycerides

A

Inhibiting ATP production eventually blocksglucose uptake from the luminal side of the intestine A. True B. False

A

Membranes of organism A contain mostly FA with triple double bonds and organism B mostly single double bonds. ______ will most likely adapt to extremely cold temperatures A. Organism A B. Organism B

A

One of the most important roles of selectins is to_____ A. Mediate adhesive contacts to construct tissues and organs in the embryo B. Slow down and recruit leukocytes during inflammation C. Mediate adhesion between non-immune cells during neural development

A

To completely oxidize a 10C fatty acid, ___ cycles of β-oxidation must occur. A. 3 B. 4 C. 5 D. 6E. 10

B

What is the role of NAD+ in the process of cellular respiration? A. It functions as an enzyme B. It functions as an electron carrier C. It is the final electron acceptor for anaerobic . It is a nucleotide source for the synthesis of ATPE. It generates energy in photosynthetic reactions

B

What would be the effect of exposing an embryo to laminin-specific neutralizing antibodies? A. All the processes of cell migration would stop B. Migration of primordial germ cells would stop C. Migration of neural crest cells out of the neural plate would stop. D. Migration of all lymphoid cells would stop.

B

Which is the main purpose of the unfolded protein response (UPR)? A. To synthesize new proteins B. To alleviate stress in the ER after an accumulation of misfolded proteins C. To ensure that glycoproteins are properly folded before movement to the Golgi complex D. To stop all protein synthesis in the cell E. To transfer sugar residues onto a nascent polypeptide

B

Which of the following is NOT a property of enzymes? A. Most enzymes are proteins B. They are altered irreversibly during the reaction C. They are required in small amounts D. They do not affect the thermodynamics of the reaction

B

Which of the following is TRUE about red blood cells A. They contain an extensive endomembrane system B. They lack nuclei and most cytoplasmic organelles. C. They are rich in lysosomes D. They are rich in mitochondria E. They have different lipids in their membrane

B

Which of the following organelles are part of the endomembrane system? 1. Lysosomes 2. Golgi complex 3. Nucleus 4. Plasma Membrane 5. Mitochondria A. 1, 2 and 3 B. 1, 2 and 4 C. 1, 2, 3 and 4 D. All except the plasma membrane E. All except the nucleus

B

Which one of the following is formed by the removal of a carbon (as CO2) from a molecule of pyruvate? A. ATP B. Acetyl CoA C. Citrate D. Water E. Oxaloacetate

B

____ serves as a storehouse of surplus chemical energy in animals while most plants bank their surplus of chemical energy as ______ A. Glycogen; Cellulose B. Glycogen; Starch C. Cellulose; Glycogen D. Starch; Glycogen E. Cellulose; Starch

B

lTo which sides do the N terminus and C terminus face in the given integral protein (from the worksheet)... C-terminus a. . The N-terminus faces the cytosol, while the C terminus faces the ER lumen B. The N terminus faces the ER lumen, while the C terminus faces the cytosol

B

"Property of an atom to attract electrons towards itself" best defines: A. Polarity B. Electronegativity C. Electromagnetic charge D. Atomic number E. Boiling point

B, electronegativity

All proteins have tertiary and quaternary structure A. True or B. False

B, false

The transformation of water to ice at 10°C has a ΔG = 154. Therefore, this can be considered a spontaneous reaction A. True B. False

B, false

The Na+/glucose transporter moves substances across the membrane using: A. Simple diffusion B. Facilitated diffusion C. Diffusion through an ion channel D. Primary active transport E. Secondary active transport

E

The source of energy for primary active transport is usually ____ A. Electrochemical gradient B. Concentration gradient C. Increase in entropy D. Glucose oxidation E. ATP hydrolysis

E

Transfer of high energy electrons from NADH is associated with translocation of _____ H+, while FADH2is associated with the translocation of _____ H+ A. 8; 10 B. 10; 8 C. 8; 6 D. 6; 8 E. 10; 6

E

____ induce a rotation of 120° causing, the release of 1 ATP. A full rotation of the ring produces ___ ATPs A. Four protons; Three B. Three protons; Three C. Two protons; Four D. Three protons; Four

a

Which of the following happen in the Golgi Complex? A. Proteins are sorted to their final destination B. More amino acids are added to proteins C. More sugars are added to glycoproteins D. Escaped proteins are retrieved if they have an N-terminus signal sequence

a and c

Which of the following statements about the basement membrane is true? A. It is the place where most metabolic enzymes are found in epithelial cells B. It is rich in sodium and potassium channels C. It provides mechanical support for attached cells D. It is one of the layers of the extracellular matrix

CandD

If your cells are now transferred from 15 °C to 37 °C , how would this affect the fatty acids and the activity of membrane desaturases? A. Saturation decreased, desaturases increase B. Saturation decreased, desaturases decrease C. Saturation increased, desaturases increase D. Saturation increased, desaturases decrease

D

How many carbons from the original pyruvate enter the Krebs cycle?

2

The breakdown of 16-C fatty acid yields (from β-oxidation cycle): A. 7 NADH, 7 FADH2, and 8 Acetyl CoA B. 5 NADH, 5 FADH2, and 6 Acetyl CoA C. 6 NADH, 7 FADH2, and 8 Acetyl CoA D. 8 NADH, 7 FADH2, and 8 Acetyl CoA E. 6 NADH, 6 FADH2, and 7 Acetyl CoA

7 NADH, 7 FADH2 , and 8 Acetyl CoA

How are plasma membrane proteins embedded in the membrane? A. A ribosome travels to the plasma membrane during protein synthesis and a protein complex helps insert the protein directly in the PM B. A ribosome travels to the ER membrane during protein synthesis and a translocon helps insert the protein in the ER membrane

?

"Events in the universe tend to go downhill" in the second law of thermodynamics means that: A. Energy cannot defy gravity B. Reactions always occur from high energy states to low energy states C. Gravity is the ultimate force that drives cellular metabolism D. Once a reaction occurs, it is always irreversible

B

"pH at which a functional group is half ionized and half unionized" best describes A. pH B. pK C. pI

B

At equilibrium, the concentration of reactants and products is always equal A. True B. False

B

Binding of neurotransmitters to receptors on the postsynaptic membrane, opens _________ channels A. Voltage - gated B. Ligand - gated C. Mechano - gated

B

HSP60 and HSP70 are called Heat Shock Proteins because A. They are only synthesized in cells exposed to temperatures of exactly 60 ºC and 70 ºC B. Their synthesis increases in cells exposed to heat C. The decades (1960 and 1970) when they were discovered D. They are denatured at 60 ºC and 70 ºCE. The scientists that discovered them were in shock when they finally isolated them

B

If all hydrocarbon tails of phospholipids were saturated, ____ A. The bilayer would be more fluid B. The bilayer would be less fluid C. The bilayer would not be affected

B

If the neurotransmitter triggers the opening of anion selective channels, this will induce a _____ membrane potential A. Less negative B. More negative

B

If your cells are now transferred from 15 °C to 37 °C , how would this affect the fatty acids and the activity of membrane desaturases? A. Saturation increased, desaturases increase B. Saturation increased, desaturases decrease C. Saturation decreased, desaturases increase D. Saturation decreased, desaturases decrease

B

In a molecule of hydrogen fluoride (HF), electrons are _____ attracted to _____ atom(s). A. Equally; Both B. Less; Hydrogen C. Less; Fluorine

B

In most mammalian cells, there is a voltage difference across the membrane. At rest, how is the inside of the cell charged, relative to the outside of the cell? A. The inside is more positively charged B. The inside is more negatively charged

B

Inhibiting ATP synthesis directly inhibits glucose uptake from the intestinal lumen A. True B. False

B

Membranes contain a wide diversity of lipids, including A. Triglycerides, cholesterol and phosphoglycerides B. Cholesterol, phosphoglycerides and sphingolipids C. Phosphoglycerides, sphingolipids and triglycerides D. Cholesterol, triglycerides and sphingolipids

B

Molecular chaperones are NOT involved in A. Encouraging protein folding B. Accelerating protein synthesis C. Preventing protein aggregation D. Preventing nascent peptides from binding to other cytosolic proteins

B

Protein glycosylation is the process by which A. More amino acids are added to some proteins in the Golgi complex B. Carbohydrate molecules are added to some proteins C. Lipid molecules are added to some proteins in the Golgi complex D. Proteins are properly folded in the ER

B

The ____ end of microtubules is associated with the centrosome. The ____ end is situated at the opposite (growing) tip A.Plus; Minus B.Minus; Plus C.Minus; Minus D.Plus; Plus

B

The relationship between the concentration of the reactants and products at equilibrium, best defines A. Dissociationconstant, Kd B. Equilibrium constant, Keq C. Standard free energy change, ΔG°' D. Enthalpy, ΔH

B

These images illustrate the experiments that demonstrated ___ A. Platelets are responsible for blodclotting B. Integrins interact with extracellular proteins via conserved RGD sequences C. Blot clots can only be formed if RGD peptides are added

B

If a protein needs to end up in the plasma membrane, it will A. Become embedded in the membrane after it is glycosylated B. Become embedded in the membrane after being released by the Unfolded Protein Response (UPR) C. Become embedded in the ER membrane during translation D. Become embedded in the membrane by a plasma-membrane bound ribosome

C. become embedded in the ER membrane during translation

A K+- transporting ion channel in the plasma membrane of animal cells that remains open even in a "resting" cell, best describes A. Cation-gated K+ channels B. Ligand-gated K+ channels C. Na+/K+ leak channels D. K+ leak channels E. Resting potential K+ channels

D

A cell has enough available ATP to meet its needs for about 30 seconds. What is likely to happen when an athlete exhausts his or her ATP supply? A. They have to sit down and rest. B. ATP is transported into the cell from the circulatory system. C. Other cells take over, and the muscle cells that have used up their ATP cease to function. D. Catabolic processes are activated that generate more ATP.

D

A stretch of 6-15 hydrophobic amino acids known as ______, is usually located in the _____ of _______ A. Transmembrane domain; C-terminus; Secretory proteins B. Translocon; C-terminus; cytosolic proteins C. Signal sequence; N-terminus; Secretory proteins D. Signal peptide; N-terminus; Mitochondrial proteins E. Ribozyme; C-terminus; chloroplastic proteins

D

All thermodynamically favored reactions release energy and have a ______. These spontaneous reactions are known as ___ A. +ΔG; Endothermic B. -ΔG; Exothermic C. +ΔG; Endergonic D. -ΔG; Exergonic

D

Breaking bonds consumes energy. Rank the following types of bonds based on their stability or amount of energy input (highest to lowest) they need be broken: A. Hydrogen bond, Ionic bond, Covalent bond, van der Waals forces B. Ionic bond, Covalent bond, Hydrogen bond, van der Waals forces C. Van der Waals forces, Ionic bond, Hydrogen bond, Covalent bond D. Covalent bond, Ionic bond, Hydrogen bond, van der Waals forces

D

Drugs such as prozac, cocaine and amphetamines affect synaptic transmission events by A. Altering the reuptake of neurotransmitters B. Increasing the release of neurotransmitters C. Extending the presence of neurotransmitters in the synaptic clefts of the limbic system D. All of the above are correct

D

Enzymes involved in membrane remodeling in response to challenging environmental conditions include all of the following except: A. Acyl-transferases B. Phospholipases C. Desaturases D. Catalases

D

How do mitochondria generate and store the energy used to produce most of the ATP made during aerobic respiration? A. By producing heat B. By generating a heat gradient C. By generating a concentration gradient D. By generating an electrochemical gradient E. By generating a Na+ ion gradient

D

Hydrolysis of _____ induces conformational change to from E1 to E2, making the ion binding site accessible to the ________ A. ADP; Cytoplasm B. ADP; Extracellular space C. ATP; Cytoplasm D. ATP; Extracellular space

D

In the absence of oxygen, organisms such as yeasts produce ethanol because A. Ethanol is a source of energy for them B. To regenerate NAD from NADH+ C. They know we like wine D. A and B are correct

D

Glycolysis produces _____ as the final product that travels to the _____ where it undergoes _____ to produce ____. A. Oxaloacetate, mitochondrial matrix, reduction, acetyl CoA B. Pyruvate, mitochondrial matrix, oxidation, acetyl CoA C. Pyruvate, intermembrane space, oxidation, oxaloacetate D. Ethanol, cytosol, reduction, oxaloacetate E. Pyruvate, inner mitochondrial membrane, oxidation, acetyl CoA

D?

What is the main purpose of the Electron transport chain (ETC)? A. To pump electrons across the inner mitochondrial membrane B. To create an electrochemical gradient across the inner mitochondrial membrane C. To synthesize ATP utilizing the high energy electrons from NADH and FADH2 D. All of the above

D?

The final electron acceptor in the ETC is _______, which accepts energy-depleted electrons and is ________ A. Oxygen; Reduced to CO2 B. CO2; Oxidized to CO2 C. Water; Reduced to CO2 D. Oxygen; Reduced to water E. CO2; Oxidized to water F. Water; Oxidized to O2

Oxygen; Reduced to water

How do drugs such as Prilosec and Zantac prevent heartburn? A. Prilosec is an irreversible inhibitor of the H+/K+ - ATPase B. Zantac interferes with histamine-binding in the parietal cells C. Both Prilosec and Zantac inhibit the Na+/K+- pump D. A and B are correct

Prilosec is irreversible inhibitor of H+/ K+ ATPase, and Both Prilosec and Zantac inhibit the Na+/ K+ pump.

What happens if some essential ER-proteins escape by accident? A. The cell will automatically undergo apoptosis B. The cell will synthesize an entire new ER to recover them C. The Unfolded Protein Response (UPR) will be activated D. They can be retrieved, if they have a special signal in the C-terminus E. They can reach the ER if they have a signal sequence in the N-terminus

They can be retrieved, if they have a special signal in the C-terminus

A and B are ends of a flagellum. A is associated with the ____ end of microtubules while B with the ____ end. Cargo from point A to point B would be transported using the motor protein _____ A.Plus; Minus; Dynein B.Plus; Minus; Kinesin C.Minus; Plus; Dynein D.Minus; Plus; Kinesin E.Minus; Plus; Myosin

a

Mannose is a type of _____. If the sorting signal for lysosomal enzymes is the presence of a phosphorylated mannose, that means that most lysosomal enzymes are ___ A. Monosaccharide; Glycosylated B. Polysaccharide; Synthesized in free ribosomes C. Lipid; Hydrophobic D. Amino acid; Hydrolyzed in the Golgi complex E. Sugar; Very sweet

a

Membrane-bound ribosomes produce many proteins that are ________, while free ribosomes produce many proteins that are _____ A. Exported from the cell; Used inside the cell B. Used inside the cell; Exported from the cell C. Used in the cytoplasm; Destined for the plasma membrane D. Used in the nucleus; Used in the cytoplasm

a

Succinate dehydrogenase is most likely synthesized by A. Free ribosomes B. ER-bound ribosomes

a

The product of anaerobic oxidation of pyruvate in muscle cells is ____, and in yeast cells is _____. A. Lactate; Ethanol B. Lactate; Glucose 6-P C. Acetyl CoA; Lactate D. Acetyl CoA; Ethanol

a

Which of the following statements about integrins is/are true? A. They anchor cells to the substrate. B. They are found in both animal and plant cells. C. Different cell types are restricted to just one type of integrin D. All of the above are true

a

Which proteins will be synthesized in ER-bound ribosomes? A. Proteins that need to end up as part of any compartment of the endomembrane system, including the plasma membrane or the extracellular space B. Proteins that need to end up in the nucleus, the cytoplasm, the mitochondria or the chloroplast

a