Cell Bio: Exam 1 - Quiz Terms

Which of the following is a reason that protein folding is a controversial topic? (Select all that apply.)

- Debates as to whether or not all of them members of a population of unfolded proteins of a single species fold along a similar pathway or fold by means of a diverse set of routes that somehow converge upon the same native state. - Debates among the types of events that occur at various stages during the following process. - Different interpretations of results that are required to study complex molecular events that occur on a microsecond timescale.

Which of the following is a reason cells are microscopic in size? (Select all that apply)

- The distance between the cell surface and interior becomes too great for the cell's needs to be met by simple diffusion. - The surface area becomes limiting as a cell increases in size

Looking at blood groups, the basic oligo with only galactose added will yield which blood type?

B

Which type of cells may be surrounded by a cell wall?

Both Eukaryotic and Prokaryotic

Which of the following is not an example of model organism?

Klebsiella pneumoniae

Ion channels that are found in either an open or closed formation are considered to be gated An example of a gated ion channel is the members of one family of cation channels that are opened and closed by the movements of stereocilia on the hair cells of the inner ear in response to sound of motions of the head. Which category does this example fall under?

Mechano-gated channel

__________ is the total chemical reactions occurring within the cell.

Metabolism

Since each enzyme molecule is only able to catalyze a certain number of reactions in a given amount of time, the velocity of the reaction approaches a maximal rate as the substrate concentration increases. The substrate concentration at which the reaction is at half-maximal velocity is called the __________ and has the symbol Km.

Michaelis Constant

Which of the following is found in Eukaryotic cells but not in Prokaryotic cells:

Mitochondrion

The properties of cells and their organelles derive directly from the activities of the __________ of which they are composed.

Molecules

The following are all amphipathic except:

Triglycerides

Which of the following is a major category of biomolecule? (Select all that apply)

Proteins Lipids Nucleic Acids Carbohydrate

What term is used to describe the expanding field of protein biochemistry?

Proteomics

Which is made of eukaryotic cells (Select All):

Protists Plants Animals Fungi

Labeling of fatty acids can be very confusing on food packaging. The type of "fats" refers to the bonding within its structure. A membrane fatty acid that lacks double bonds is considered __________?

Saturated

Which level of protein organization describes the conformation of portions of the polypeptide chain?

Secondary

Which of the following is not true of viruses? (Select all that apply)

Viruses are considered living organisms.

Smokers' bodies become accustomed to high levels of nicotine, and they experience symptoms of withdrawal when they stop smoking because the postsynaptic neurons that possess __________ are no longer stimulated at their usual level. The drug Chantix, which is marketed as an aid to stop smoking, acts by binding to the most common version of this receptor. Once bound, the Chantix molecule partially stimulates the receptor while preventing binding of nicotine.

nAChRs Receptor

Aquatic plants living in freshwater are surrounded by a hypotonic environment. Water flows into the cells, creating a __________ pressure. If the plant is placed in a hypertonic solution, such as seawater, the cell loses water, and the plasma membrane pulls away from the cell wall, causing plants to wilt. This process is known as __________.

turgor; plasmolysis

A gram of fat contains _________ the energy content of a gram of carbohydrate.

two to six times

The magnitude of __________ indicates the maximum amount of energy that can be passed on for use in another process but tells us nothing about how rapidly the process with occur.

dG

The further a reaction is kept away from a(n) ____________, the more capacity it has to do work.

equilibrium state

Water is an excellent solvent capable of forming hydrogen bonds with virtually all ___________ molecules. (Select all that apply)

- ionic - polar

What is meant by the plasma membrane being a scaffold?

Allows for fixed positions of proteins.

How many amino acids are incorporated into a protein encoded in the sequence of nucleotides in DNA?

20

Careful examination of a synapse reveals that the two cells do not make direct contact but are separated from each other by a narrow gap (synaptic cleft) of about ____________.

20 to 50 nm

How many naturally occurring elements are there?

92

A(n) __________ at one site on the membrane depolarizes an adjacent region of the membrane, triggering this againat the second site. It can only flow in the forward direction because the portion of the membrane remains in a refractory period.

Action potential

All cells need energy to fuel chemical reactions. What molecule is the readily available form of energy that cells can use called?

ATP

Plasma membranes are described in the fluid mosaic model. Why might it be important to maintain membrane fluidity (Select all that apply)?

Adapting to temperature changes Specialized protein structures Cell division Signal transduction

Bacteria have a symbiotic relationship with humans. The microbiome that resides within the intestines perform the following functions except?

Aid in pathogenesis

Cell theory describes the properties that all cells have in common. Cell theory includes (Select All):

All organisms are composed of one or more cells Cells can arise only by division from a preexisting cell The cell is the structural unit of life

Which of the following is not considered a prion disease?

Alzheimer's Disease

Using a freeze fracture technique, the picture viewed under the electron microscope revealed a specific transmembrane domain with a 20 nonpolar amino acid peptide sequence. What are we looking at?

An integral membrane protein

__________ lead to the synthesis of more complex compounds from simpler starting materials.

Anabolic Pathways

Which of the following is not true of catalysts?

As catalysts, enzymes can only decelerate the rate at which a favorable chemical reaction proceeds.

Which of the following is not true of the Cystic Fibrosis?

CFTR deficiency leads to an increase of fluid that bathes the epithelial cells of the airways.

_____ function primarily as stores of chemical energy and as durable building material for biological construction (e.g. cell walls)

Carbohydrates

You walk out of the USF library on a bright sunny day without sunscreen, even though you know better. The skin on your arms begins to turn red from the UV radiation and the DNA is damaged so your cells commit apoptosis and flake off few days later. What feature of cells is occurring throughout this process?

Cells respond to stimuli

What is the major component of plant cell walls?

Cellulose

Some proteins fold into their final confirmation by themselves; others require the assistance of nonspecific __________, which prevent aggregation of partially folded intermediates.

Chaperones

Without __________, plasma membranes would be too fluid, not firm enough, and too permeable to some molecules.

Cholesterol

In the lumen of your small intestine, the Na+/glucose symport moves sodium and glucose in the same direction working together with the Na+/K+ active pump. What specific method of transport is used?

Co-transport

What prevents digestive enzymes from digesting anything and everything in the cell?

Compartmentalization

_________ are reversible inhibitors that compete with a substrate for access to the active site of an enzyme.

Competitive inhibitors

Which type of bond has pairs of electrons that are shared between pairs of atoms?

Covalent bonds

A fertilized human egg will progress through a course of embryonic development that leads to the formation of approximately 250 distinct types of cells. Some cells become part of a particular digestive gland, others part of a large skeletal muscle, others part of a bone, and so forth. This is an example of which of the following?

Differentiation

Which of the following is a Law of Thermodynamics? (Select all that apply)

Energy cannot be created or destroyed. Events in the universe proceed from a state of higher energy to a state of lower energy

Cell differentiation in mammals is irreversible.

F

True or False: Viruses are considered living organisms.

F

Light energy is converted by photosynthesis into chemical energy that is stored in carbohydrates. In animal cells, energy arrives prepackaged often in the form of _________? (select all that apply)

Fatty Acids Glucose Protein

What is a common example of allosteric modulation?

Feedback Inhibition

Pyruvate, the end product of glycolysis, is a key compound because it stands at the junction between anaerobic and aerobic pathways. In the absence of molecular oxygen, pyruvate is subjected to __________.

Fermentation

This protein was discovered when it was shown that certain membrane proteins could be related by a phospholipase that specifically recognized and cleaned inositol-containing phospholipids. A rare type of anemia, paroxysmal nocturnal hemoglobinuria, results from deficiency of this protein and makes red blood cells susceptible to lysis. Which protein is it?

GPI-anchored Proteins

Liver tissue contains a carbohydrate polymer called ______ that serves as energy storage.

Glycogen

Which of the following IS NOT a pyrimidine? (Select all that apply)

Guanine

The more __________ that can be stripped from a "fuel" molecule, the more ATP that can be produced.

Hydrogen Atoms

After reviewing the reactions of glutamine formation on page 90, explain why each of the following statements concerning the third (or overall) reactions is either true or false. (Select all that apply)

If the reaction were written in in reverse, its ΔG would be 3.9 kcal/mol. If all reactants and products were at standard conditions at the beginning of an experiment, after a period of time, the [NH3]/[ADP] ratio would increase. In the cell, it is possible for glutamine to be formed when the [glutamine]/[glutamic acid] ratio is greater than one

When can viruses reproduce?

Inside a living cell

Protein conduits in the plasma membrane that are permeable to specific ions are known as __________.

Ion channels

When sodium and chlorine interact, the single electron in the outer shell of each sodium atom migrates to the electronegative chlorine atom. As a result, these two atoms are transformed into charged ____________?

Ions

In a series of reactions, A→B→C→D, it was determined that the equilibrium constant for the second reaction (B→C) is 0.1. You would expect the concentration of C in a living cell to be:

Less than one-tenth of B

The conversion of metallic iron (Fe0) to the ferrous state (Fe2+), in which the iron atom loses a pair of electronics, thereby attaining a more positive state is said to be __________.

Oxidized

Which of the following is a feature shared by prokaryotic and eukaryotic cells:

Plasma membrane

Which of the following is an example of transduction? (Select all that apply)

Plugging in a clock. Heat released during muscle contraction. Photosynthesis

In a water molecule the bond between hydrogen and oxygen is best described as a _______.

Polar covalent bond

__________ are extremely reactive and capable of chemically altering many types of molecules, including proteins, nucleic acids, and lipids.

Radicals

Cells are capable of (Select All):

Reproducting by cell division Carrying out enzymatically controlled chemical reacions Responding to stimuli Using chemical energy for activities Self-regulation Mechanical activites

Which property of the plasma member plays a critical role in signal transduction?

Response to stimuli

Who is credited with the discovery of cells?

Robert Hooke

In the cell, energy from ATP hydrolysis may be used to: (Select all that apply)

Separate charge across a membrane. Drive unfavorable chemical reactions. Donate a phosphate group to a protein. Concentrate a particular solute within the cell.

In animal cells, which of the following is a function of the plasma membrane? (Select all that apply)

Substance transport Selectively permeable barrier Scaffold for biochemical reactions Compartmentalization

A noncompetitive inhibitor does not prevent the enzyme from binding its substrate. What will be the effect of increasing the substrate concentration in the presence of a noncompetitive inhibitor? Do you expect a noncompetitive inhibitor to affect the enzyme Vmax? Km?

The Km would be unaffected and the rate of activity will increase towards the new Vmax.

All chemical reactions within the cell are reversible, and therefore we must consider two reactions occurring simultaneously, one forward and the other in reverse. According to ___________, the rate of a reaction is proportional to the concentration of the reactants.

The Law of Mass Action

Which of the following is not true of active sites?

The binding of substrate to enzyme at the active site is accomplished by covalent bonds.

What is meant in terms of concentration ratios when it is said that the ΔG of ATP hydrolysis in the cell is approximately -12 kcal/mol, whereas the ΔG0' is 7.3 kcal/mol?

The ratio of ATP/ADP in the cell is much greater than that at standard conditions.

How can you visualize cells?

Using a microscope

Intestinal cells, by increasing folds within the plasma membrane create __________ in order to increase surface area for aiding and capturing materials in digestion.

Villi

What is the most abundant substance in the cell?

Water

Qualification(s) must be met before a molecule can diffuse passively across a plasma membrane. Those qualification(s) are: (Select all that apply)

material must be hydrophobic material must be small