Exam 2-Biology

Exocytosis

Waste materials stored in the cytoplasm are released from the cell

which of the following is true of enzymes?

-Enzyme function is influenced by physical and chemical environment factors such as pH and temperature. -Enzymes may require a nonprotein cofactor or ion for catalysis to take place. -Enzymes increase the rate of chemical reaction by lowering activation energy barriers. THE ANSWER IS ALL OF THE ABOVE.

Three-dimensional shape.

The tertiary structure of a protein in the

Isotonic

A cell with an internal concentration of 0.02 molar glucose is placed in a test tube containing 0.02 molar glucose solution. Assuming that glucose is not actively transported into the cell, which of the following terms describes the internal concentration of the cell relative to its environment?

Denaturation.

A change in a protein's three-dimensional shape or conformation due to disruption of hydrogen bonds, disulphide bridges, and ionic bonds is termed

Endergonic

A chemical reaction that has a positive ΔG is correctly described as

kinetic energy

A rock rolling down a hill is exhibiting

direct chemical transfer of a phosphate group

ATP generally energizes a cellular process by

The Binding of the substrate changes the shape of the enzyme slightly.

According to the induced fir hypothesis of enzyme function, which of the following is correct?

the entropy of the universe is constantly increasing.

According to the second law of thermodynamics,

Enzyme Synthesis.

All of the following are functions of integral membrane proteins except

Enzymes provide activation energy for the reaction they catalyze.

All of the following are true of enzymes except

exocytosis.

All of the following processes take material into calls except

Both sides of a membrane are identical in structure and function.

All of the following statements about membrane structure and function are true except?

Surface Area

An increase in which of the following parameters is most important in the evolution of specialized exchange surfaces such as the linings of the lungs or intestines?

Facilitated Diffusion

Carrier proteins assist with the diffusion across the membrane

hypertonic to fresh water but hypotonic to the salt solution.

Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a salt solution become limp and soft. From this we can deduce that the cells of the celery stalks are

Enzyme

Chemical reactions of metabolism within cells are regulated by organic catalysts. What are these catalysts called?

is consistent with the second law of thermodynamics.

Evolution of biological order

Simple Diffusion

Examples include food coloring in water and oxygen in our blood

Phagosytosis

Food particles are engulfed and ingested by the cell

By lowering the energy of activation of a reaction.

How does an enzyme catalyze a reaction?

TAACGT.

If one strand of a DNA molecule has the sequence of bases ATTGCA, the other complementary strand would have the sequence

it is available to do work.

In an organism, the energy available to do work is called free energy because

electrochemical gradients.

Ions diffuse across membranes down their

-breakdown of macromolecules. -synthesis of macromolecules. -control of enzyme activity. Answer is all of the above.

Metabolism is best described as

Activation Energy.

Molecules capable of interacting must first overcome a thermodynamic barrier known as the reaction's

Nucleus

Most of a eukaryotic cell's genes are found in the

maintain membrane fluidity.

One of the functions of cholesterol in animal call membranes is to

Osmosis

Special name for the movement of water across membranes

binds with the substrate.

The active site of an enzyme is the region that

Pinocytosis

The cell ingests liquid and/or dissolved solute

Curve 4

WHICH CURVE WAS MOST LIKELY GENERATED FROM ANALYSIS OF AN ENZYME FROM A HUMAN stomach where conditions are strongly acid?

small and hydrophobic.

The kinds of molecules that pass through a cell membrane most easily are

Feedback inhibition.

The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is known as

active transport.

The movement of a substance across a biological membrane against its concentration gradient with the help of energy input is which of the following?

Complementary pairing of the bases.

The structural feature that allows DNA to replicate itself is the

Energy Coupling

The transfer of free energy from catabolic pathways to anabolic pathways is best called

Co-enzyme

What is an organic, non-protein component of an enzyme molecule called?

Glycoproteins

What membrane-surface molecules are thought to be most important as cells recognize each other?

Entropy of the universe.

Whenever energy is transformed, there is always an increase in the

Peptide bonds

Which bonds are created during the formation of the primary structure of a protein?

DNA → genes → RNA → proteins

Which of the following best describes the relationship between proteins, RNA, DNA, and genes in humans?

It exhibits a specificity for a particular type of molecule.

Which of the following is a characteristic feature of a carrier protein in a plasma membrane?

Energy cannot be created or destroyed.

Which of the following is part of the first law of thermodynamics?

The products have less free energy than the reactants.

Which of the following is true for exergonic reactions?

They release energy as they degrade polymers to monomers.

Which of the following is true regarding catabolic pathways?

It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.

Which of the following statements is correct about diffusion?

They are usually coupled with anabolic pathways to which they supply energy in the form of ATP.

Which of the following statements is true concerning catabolic pathways?

A Substrate molecule bound to an active site affects the active site of several subunits.

Which of the following statements is true regarding enzyme cooperativity?

Enzymes increase the rate of reaction.

Which of the following statements regarding enzymes is true?

Exergonic

Which of the following terms best describes the reaction?

negative ΔG, spontaneous

Which of the following terms best describes the reaction?

Catabolism

Which term most precisely describes the general process of breaking down large molecules into smaller ones?

cofactor necessary for enzyme activity

Zinc, an essential trace element, is presented in the active site of the enzyme carboxypeptidase. The zinc most likely functions as a(n)

Facilitated diffusion.

all of the following membrane activities require ATP energy except

An α-helix of a polypeptide

figure 5.7 shows