Bio midterm 1 study

Which of the following statements concerning catabolic pathways is TRUE?

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

Which of the following statements about the Golgi apparatus is TRUE?

Vesicles that bud off from the trans side of the Golgi apparatus have molecules on their surfaces that can recognize "docking" sites on the surface of the plasma membrane.

Cellulose is

a polysaccharide found in plant cell walls.

The proteins found in chloroplasts

are encoded either by DNA in the chloroplast or by nuclear DNA

A major function of the smooth endoplasmic reticulum is the synthesis of

lipid

Of the following, the greatest electronegativity would be exhibited by an atom having

nine protons in its nucleus and seven electrons in its second electron shell.

Hydrogen bonds form between the hydrogen atoms of water molecules and

oxygen atoms of other water molecules.

Which of the following membrane activities do NOT require energy from ATP hydrolysis?

passive diffusion, movement of solutes by carrier/channel proteins

Glycerol is a component part of

phospholipids.

Vacuoles may act as

places to store reserves of important organic molecules

Which of the following statements is FALSE?

sulfhydryl groups act as bases.

The function of the nucleolus is the

synthesis of ribosomes.

An enzyme's specificity is dependent on the

tertiary structure of the enzyme.

G=H-TS

G = Gibbs free energy H = enthalpy T = temp in K S = entropy

According to the second law of thermodynamics, a reaction that has a large negative ΔG:

is exergonic and will yield energy.

Which of the following statements about ATP and ADP is TRUE?

ATP acts as an allosteric inhibitor of many enzymes in catabolic pathways while ADP acts as an allosteric activator of many enzymes in catabolic pathways.

A particular molecule has a single carbon atom, which is covalently bound to four other atoms. The four atoms to which the carbon atom is bound are each from a different element. In other words, the molecule has a total of five atoms, each from a different element, one of which is carbon. Which of the following statements about this molecule is (are) true?

It would be theoretically possible to design a molecule that would be an enantiomer of the above molecule.

Which of the following statements about membrane synthesis is TRUE?

Membrane proteins are synthesized in the rough ER and membrane lipids are synthesized in both the smooth and rough ER.

Ribosomes consist of

RNA and protein.

Which of the following statements about protein structure is most accurate?

Secondary structure is determined by interactions between the repeating constituents of the polypeptide backbone and tertiary structure is determined by interactions between amino acid side chains.

Which of the following is NOT an example of discovery science?

Testing the prediction that mimicking the coloring of poisonous snakes will protect non-poisonous snakes from predation.

Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?

a. Dehydration reactions generally occur during anabolism and hydrolysis reactions generally occur during catabolism. b. Dehydration reactions assemble polymers and hydrolysis reactions break down polymers. *C. ALL d. Macromolecular synthesis occurs through the removal of water and digestion occurs through the addition of water.

When an electron moves from a lower energy level to a higher one, it

absorbs energy.

Acid or base: carboxyl

acid

Acid or base: sulhydryl

acid

The concentration of iodine in the cells of the thyroid gland is many times greater inside the cells than outside them. This situation could be maintained by

active transport of iodine across the plasma membrane.

All of the following are part of a prokaryotic cell except

an endoplasmic reticulum

Acid or base: amino

base

The ionic bond of sodium chloride is formed when

chlorine gains an electron from sodium.

Which structure of the cell is important in movement of organelles, cell shape, and cell motility?

cytoskeleton

Scientists choose among competing hypotheses by

discarding those hypotheses that make false predictions.

Ions always diffuse across membranes down their

electrochemical gradients

Ions and large polar molecules do not readily diffuse through the phospholipid bilayer of the cell membrane because the

fatty acid tails of the bilayer form a hydrophobic barrier.

In the reaction of A + B ---> C , the forward reaction has a negative value of ΔG. This means that the reaction

has the thermodynamic potential to proceed from left to right, but in the other direction upon the addition of free energy.

DNA is usually found in a double-stranded state. The two strands are held together by

hydrogen bonds between the bases of one strand and the complementary bases of the other.

The pH in a cellular compartment is lowered from pH=7 to pH=5. The effect on proteins in this compartment will be

important because the hydrogen ion concentration has increased 100-fold and protein conformation will probably be altered.

The order of chemical bonds from easiest to hardest to break is

van der Waals interactions, hydrogen bonds, ionic bonds, covalent bonds (VHIC)

ATP + H2O ---> ADP + Pi. This reaction

yields useful energy to cells.