Cell molecular biology

binds substrates in a manner that facilitates the formation of product

Enzyme

Which of the following is an enzyme?

Carboxypeptidase

A sick person often has a fever, which can inhibit the growth of bacteria because?

enzymes don't function as well at temperatures other than the optimal temperature

The equation AB+H20 A+B would be catalyzed by which of the following classes of enzymes

hydrolases

An allosteric inhibitor

binds at the regulatory site

A competitive inhibitor

cannot be processed as a substrate by the enzyme

A prosthetic group in an enzyme

is located in the reaction center, assists in catalysis

An increase in temperature activates chemical reactions by?

increasing the number of molecules with energy high enough to undergo the reaction

Catalyst is an agent that?

enhances the rate of the reaction

Aspirin binds to the prostaglandin synthetase and permanently stops its ability to produce prostaglandin. This is an example of?

Irreversible inhabition

Fireflies have the ability to convert the energy in ATP to light. Which of the following types of work is performed

bioluminescent

Nerve impulses travel along the neurons by the opening of channels that allow sodium ions to flow inward, followed by an outward flow of potassium ions. In order to ensure that the impulse may be produced at any time, sodium is actively transported out of

concentration

The statement, the total amount of energy in the universe is constant,

is a tenet of the first law of thermodynamics

Negative free energy change indicates that?

the reaction is exergonic

Aerobic refers to what property of chemotrophs?

requires oxygen to produce energy

CO2 generally enters the plant through pores called?

Stomata

in chloroplast, the stroma, is the?

central semifluid region

which statement accurately describes the Calvin cycle?

carbon fixation, CO2 is reduced to organic sugars, occurs in chloroplast stroma, a carbon assimilation process

the calvin cycle occurs in the ?

Stroma

in the Calvin cycle, the enzyme that catalyzes the capture of carbon dioxide and the formation of 3-phosphoglycerate

ribulose bisphosphate caboxylase/ oxygenase (rubisco)

biosynthesis of sucrose occurs in the?

cytoplasm

breakdown of glucose to pyruvate by a cell is an example of?

catabolic

negatively charged phosphates of ATP influence one another by?

charge repulsion

gross output of ATP from glycolysis is 4, where as the net output of ATP is ?

2

during strenuous exercise, you may notice your muscles burn

w/o Oxygen, pyruvate is being converted to lactic acid

energy in the cell can be stored by accumulating reduced compounds because?

reduction reactions are endergonic, oxidation reactions are exergonic

phosphate cleavage of starch or glycogen polymers involves?

using phosphate to break the bond between monomers

products of glycolysis are?

ATP, NADH, Pyruvate

in aerobic conditions, pyruvate generated during glycolysis is converted to?

acetyl CoA and used in aerobic respiration

Gluconeogenesis occurs in the

liver

Is not a production of the TCA cycle?

acetyl CoA

Would not be used as a final electron acceptor in anaerobic respiration

oxygen

Resting potential of a particular nerve cell is -66mV. Depolarization of the membrane will shift the membrane potential toward

0 mV

based on graph, what period of time sodium channels start to inactivate

1msec

graph above, what point in the action potential does repolarization

C

graph above, at the same time that stimulus was introduced, a drug that specifically inhibits sodium channels was added to the system. Effect this would have is that the membrane would

not depolarize

the knee-jerk reflex circuit includes activation of the following neurons

sensory, interneuron, and motor innervating the extensor muscle

structure of an ion channel, the gate and the selectivity filter

can be different parts of the channel molecule

your record amplitudes of 0,2,6,8 pA in a single channel experiment. How many channels are in this patch

2

the order of events in an action potential is

activation of sodium channels, activation of voltage-gated potassium channels, inactivation of sodium channels, closing of voltage-gated K+ channels

the main differences between electrical and chemical synapse are?

electrical is faster and bidirectional

signaling distance is increasing in the following order

synaptic, paracrine, endocrine signaling

Transport systems involved in maintaining low calcium ion concentration in the cytoplasm are

ER Calcium pump, plasma membrane calcium pump, and calcium/sodium exchanger

Nitric Oxide signaling is involved in regulation of?

smooth muscle relaxation

Not a function of cytoskeleton

passive transport

Correct sequence of microtubule assembly

tubulin dimers, oligomers, protofilaments, sheets of protofilaments, closing of microtubule, elongating microtubule

Not a function associated with the cytoskeleton

anchoring site for mRNA during transcription

Striated muscle has?

light (I-bands) and dark bands (A-bands).

What takes place as muscle contracts?

I band gets smaller, H zones get smaller, Z lines get closer together

In relaxed muscle, calcium is found in high concentration in the?

sacroplasmic reticulum

when glucose is converted to glucose-6-phosphate by hexokinase, the accumulation of glucose-6-phosphate inhibits the reaction

Feedback inhibition

A foreign substance is added to the reaction in part a above. The substance binds to the hexokinase and prevents its ability to catalyze the reaction

non-competitive inhibition

An inactive form of an enzyme becomes active after being phosphorylated

covalent

An increase in temperature activates chemical reactions by

increasing the number of molecules with energy high enough to undergo the reaction

Which type of microscope has the greatest resolving power?

electron

Single channel recording is a

technique that allows to measure electrical currents through a single ion channel molecule

The movement of water through a membrane from an area of high concentration to an area of low concentration is known as

osmosis

Cellulose is a polymer of _____, a common monosaccharide.

glucose

While fishing, a biology student makes the following observations: 1) water spiders may be walking on water, 2) flat rocks may be made to skip across the water. Which of the following properties of water can explain these observations?

Water molecules are associated via hydrogen bonds

The rate of facilitated diffusion is limited predominantly?

the number of transport proteins in the membrane

Which of the following is true of a nanometer?

A nanometer is one millionth of a meter

Which of the following is NOT a function of membranes?

Information storage

The two most important properties that allow a molecule to cross a phospholipid simple diffusion are?

polarity and size

Which of the following biological polymer is mismatched with its monosaccharide?

Cellulose-fatty acid

Why can't Glucose cross the lipid bilayer?

Because it is too large

The polarity of water is caused by the _______.

unequal sharing of electrons between oxygen and hydrogen atoms.

Substances that can readily pass through the cell membrane are chemically ______ by nature.

non-polar

CFTR belongs to?

ABC transporters

Which is the strongest of the following forces that stabilize protein structure in solution?

Covalent Bonds

V-type ATPase

pumps protons into vesicles

Which of the following is the smallest?

Proteins

One of the strategies for a single cell to increase its membrane transport efficiency is ?

cytoplasmic streaming

You are designing a protein that will transport potassium into the cell which protein will it be?

ATPase

Biologically, which of the following is the least important characteristics?

Water typically contains isotopes of hydrogen

Ribosomes that do not anchor to the surface of the rough endoplasmic reticulum during translation most probably are?

synthesizing cytoplasmic proteins

The hydropathy plot of a protein shows four hydrophobic regions. Which protein is true?

The protein has four hydrophobic domains

Which of the following is a disaccharide?

Lactose

The main differences between plant and animal cells are?

chloroplasts, vacuoles, and cell wall

The transport of two molecules across the cell membrane in opposite direction is called?

Antiport

A voltage-gated calcium-activated chloride channel is activated by?

membrane voltage and calcium conducts chloride

Which of the following is NOT a tenet of the cell theory?

All cells have a membrane bound nucleus

1 m=

1,000,000nm

1nm=

1/1000000

Cellulose belongs to which of the following groups of macromolecule?

Polysaccharide

________ are liquid at room temperature, while __________ are solid.

Unsaturated fatty acids , saturated fatty acids

Which of the following can ONLY be viewed by electron microscopy?

Viruses

Diffusion is a trans membrane movement of a substance with the concentration gradient, with?

no involvement of membrane proteins

Trypsin is a hydrophilic protease enzyme and cannot cross the plasma membrane. It can however, cut the hydrophilic parts of the proteins that are exposed to the extracellular environment. When the cells are treated with trypsin, in how many fragments will

4

Sedimentation coefficient is?

a ratio between the velocity of the particle and the acceleration during centrifugation

Cells of the pancreas produce and directly release enzymes of the digestive system. The type of secretory mechanism associated with the pancreatic cells is?

regulated secretion

Which of the following organelles are not part of the endomembrane system?

mitochondria

Smooth ER functions in drug detoxification process by?

adding hydrophobic residue to hydrophilic drugs

Transport of vesicles from plasma membrane to Golgi to ER is called?

retrograde transport

Clathrin lattice assembly is similar to?

soccer ball

Endocytosis involves?

invagination of the plasma membrane, trapping particles and internalizing

Rough ER is involved in?

protein synthesis and cotranslational insertion, protein maturation, removal of misfolded proteins (all of the above)

Which of the following statements is false regarding phagocytosis?

It involves the projection of pseudopodia

A protein is destined to be secreted from a cell in which of the following you expect to find the protein first?

Golgi apparatus

Which of the following cell junctions are associated with the proper alignment of epithelial cells?

(all of the above) gap junctions, tight junctions,desmosomes, adhesive junctions

Which of the following is NOT associated with the adhesive junctions?

Plaques or connexin

Heterotypic interactions of the cell adhesion proteins involve?

the different proteins from different cells

You are studying the effects of calcium influx on vesicle release. If channel blocker, you would expect?

No release

Tight junction is mostly permeable to?

Cations

With regard to the semi-permeable nature of the plasma membrane, which of the following would readily cross it without the aid of a transport protein?

Water

Transmembrane movement of a substance along its concentration gradient is?

Active transport

The cells with the largest single dimension in our bodies are?

Oocytes

A scientist is examining motile protozoa. He wishes to determine their direction of movement. Which of the following microscopic techniques is LEAST likely to be used to view these cells?

Electron Microscopy

The isotonic medium

has the same concentration of solutes as the cell.

During receptor-mediated endocytosis, the ultimate fate of the vesicle and/or its contents include(s)?

Transport to late endosome for digestion, transcytosis, recycling of receptors (choice A,B, and C)

Based on your knowledge of the chemistry of the cell membrane, which of the following compounds would you couple with a new drug in order to achieve better uptake by the cells?

Lipids

Collagens are associated with which of the following types of cellular junctions?

None of Above

Which of the following is NOT soluble in water?

Lipids

Ion channels participate in what type of membrane transport?

Facilitated diffusion

Which of the following sequences correctly lists the hierarchical nature of cellular structure from smallest to largest?

Small molecules, macromolecules, macromolecule complexes, organelles.

Why is a selectively permeable membrane so important to living cells?

It provides a good barrier between the inside and the outside of the cell

Cystic fibrosis is the result of malfunction of the cell in transporting which of the ions?

Cl-

You have genetically engineered a yeast cell to make a protein that will ultimate secreted from the cell. If all is functioning well, in which order (first to last) find the protein in the cell until it is secreted?

ER-Golgi-secretory vesicle-environment

The energy for loading a neurotransmitter into a secretory vesicle?

A proton gradient established by the proton pump on the (second choice b)

Interphase is?

a growing phase between cell divison

Mitotic index is?

% of cells in interphase

A decision to divide again or arrest & terminally differentiate is taken during the following period in the cell cycle

G1

The mitotic index of cells in a certain tissue is usually around 3-5%. You take a sample of the tissue & determine the mitotic index is 20%. What do you think is happening?

There's a possibility of tumor developing.

Chromosomes are attached to the mitotic spindle

by the kinetochore & by the connection in the centromere region

The correct stages of mitosis is?

Prophase, Metaphase, Anaphase, & Telophase

The amount of DNA a zygote gets from an egg & sperm is?

More from an egg

In asexual reproduction, progeny

can be identical to the parent

Advantages of sexual reproduction include the following

beneficial traits can be combined, beneficial mutations can be combined, & genes' reshuffling is possible

An organism has 2 copies of each of the homologs chromosomes, this organism is?

Diploid

An organism shows a dominant trait. It's genotype for this trait can be?

YY, Yy

Meiosis involves the following # of cell divisions

2

Crossing over occurs in?

Prophase I of meiosis

An example of purine is?

Guanine

DNA isolates from aspergills has adenine content of 25%. Based upon this info, what is the % of G-C w/in the Asperigills DNA?

50%

Which of the following are components of Chargaff's rule of bases?

(C+T=A+G,); A=T; purines = pyrimidines, G=C

The normal gene for hemoglobin was isolated, cloned and subjected to restriction enzyme digestion w/ BAM HI. Following gel electrophoresis, 3 bands are routinely obtained. However, following the same procedure w/ the hemoglobin gene from an individual wit

Mutation associated with sickle cell anemia results in the gain a Bam HI cut site.

The phase of the cell cycle associated with the doubling of the amount of DNA in the cell?

S phase

The difference btwn RNA & DNA involves different?

nucleotide composition, backbone sugar, single & double stranded structure

Okazaki fragments are part of the synthesis of the?

DNA lagging strand

How many pieces of double stranded DNA will you have after 2 cycle of PCR if you start with 2?

8

DNA replication is initiated by the synthesis of a?

RNA primer

DNA damage may include

Deamination, depurination, thymine dimer formation

Genetic code is degenerate because?

a given amino acid can be encoded by more than 1 nucleotide triplet

Which DNA mutation are more devastating: single, double, triple?

Depends on the location of mutation

Griffin's experiment on bacterial transformation, showed that?

Bacteria can take up DNA molecules from the enviroment

UV light treated bacteria would most likely have DNA damage in the form of?

Pyrimidine dimer formation

The longest phase of the cell cycle is?

Interphase

During metaphase in mitosis, how many telomeres are present in a cell is which 2n = 12

48

The genotype of particular pea plant in TtYy, corresponding to a phenotype of tall & yellow. How many different types of gametes are expected to be produced by this individual?

4

During gametogenesis _____ sperm cells are made from one and ______ egg cells are made from one Oocyte

4,1

One cat carries heterozygous, long haired traits (Ss) & it mate carried homozygous SS traits (ss). Use a Punnett square to determine the probability of one of their offspring having long hair.

50%

How many nucleotides do you need to encode for Ala-Val-Ser-Pro-Ser peptide?

15

In studying T cell divisions in response to specific antigen, you decide to ... these T cells with antigen and examining the gases that are activated by the interactions to do this, following information you should involve?

mRNA

The enzyme RNA polymerase binds

to the promoter region

Transcription factors

regulate gene expression

You are examining an enzyme associated w/ glycolysis. As such, you would expect the

protein to be constitutively expressed

The situation in which an active regulatory protein "turns on" expression is an example of

Positive control

tRNA moves through the ribosome complex in the following order

aminoacyl site, peptidyl site, exit site

The anticodon on the tRNA

is complementary to the nucleotide triplet (codon) on mRNA

mRNA cap

increases mRNA stability, helps mRNA positioning in the ribosome & helps mRNA recognition by ribosomes

Poly(A) tail on mRNA

is protective against degradation, increases stability, can help recognition, helps transport from by the ribosome

A cell that has lost its capacity to grow in vitro as a monolayer and has strated growing suspended in the media is now?

anchorage independent

The classification of cancers into carcinomas, sarcomas, & lymphomas is based on?

Which cells gave rise to the cancers

In cancer, cell division is uncoupled from cell differentiate. What does it mean?

Normally, when cells divide, 1 can differentiate, 1 keeps dividing. In cancer, both can keep dividing

The correct order of events in metastasis of a cancer is?

Angiogenesis, Invasion, Transport, New site

What is a minimal number of nucleotides you need to mutate to change to?

9