Biology 1013 - Exam 2

Where, specifically, does the citric acid cycle (Krebs cycle) occur?

Matrix of the mitochondria

The first detectable molecule following the _______ of carbon dioxide in a C4 plant is a four carbon molecule.

fixation

In a redox reaction, reduction means ________, and oxidation means ________.

gain of electrons; loss of electrons

Which of the following is the preferred source of energy for the production of ATP in a cell?

glucose

During muscle contraction, ATP binds to ____ filaments, which change shape following ATP breakdown and bind to ____ filaments.

myosin (thick); actin (thin)

DNA, or the instructions for making proteins, is found within the _____ of the cell; while protein synthesis machinery is found in the _____ of the cell.

nucleus; cytoplasm

When NADH donates electrons to the first carrier molecule in the electron transport chain, that carrier molecule is re-energized. oxidized. reduced.

reduced

The chlorophyll and other pigments that absorb solar energy are found within the membranes of the ______

thylakoids

As a result of glycolysis, there is a net gain of ________ ATP.

2

During the preparatory reactions, how many molecules of CO2 are produced per glucose molecule?

2

The number of ATP produced during aerobic cellular respiration from one glucose molecule is usually __________.

36-38

The outputs from the citric acid cycle are

CO2, NADH, FADH2, ATP

The amount of A, T, G, and C varies by species. Within a species the amount of A = T, and G = C. These rules were created by whom?

Chargaff

James Watson and Francis Crick contributed greatly to our knowledge of the structure of the molecule known as

DNA

Why do metabolic pathways require tens to hundreds of different enzymes?

Each enzyme has a specific substrate and produces a specific product

Molecules move from greater to lesser concentration through a carrier protein in

Facilitated diffusion

What is the best explanation as to why the amount of adenine in an organism's DNA is equal to the amount of thymine?

This is true because adenine pairs with thymine in DNA.

A coenzyme is defined as

a non-protein helper that works with an enzyme.

When a plant cell is in a hypotonic solution, the _____ ______ prevents the plant cell from rupturing.

cell wall

The polysaccharide that forms plant cell walls is _____

cellulose

mRNA contains three-base units of DNA that are called _____, each of which code for one amino acid.

codons

Where in the cell does glycolysis occur?

cytoplasm

Every energy conversion leads to a(n) ______ in the amount of disorder of a system.

increase

The changing of an enzyme's shape as the substrate binds to the active site is called the

induced fit model

If the concentration of the solute is the same in the cell as it is in the surrounding solution, the cell is in a(n) _________________ environment.

isotonic

During the process of translation, mRNA is carried to the ribosome, where it is translated into polypeptides by _____ molecules.

tRNA

The localization of the electron transport chains to the thylakoid membrane ensures that the energy released can be used to establish an H+ ion gradient the energy released is stored in the stroma NADP+ does not enter the thylakoid space CO2 remains in the stroma for the Calvin cycle reactions and does not enter the thylakoid space Glyceraldehyde 3-phosphate (G3P) is produced in the thylakoid space

the energy released can be used to establish an H+ ion gradient

When sprinting, muscle cells produce most of their ATP energy via what process?

Fermentation

Glycolysis and the citric acid cycle are similar in that they both produce __________.

NADH and ATP

Reduction of carbon dioxide is the sequence of reactions that uses _______ and ATP from the light reaction.

NADPH

Why is it beneficial to a cell for feedback inhibition to regulate the activity of an enzyme in a reaction?

This ensures that the enzyme is only active when levels of the product of the reaction are low.

Which of these words should be classified separately from the others? osmosis diffusion passive transport active transport facilitated diffusion

active transport

What are all the double-ringed purines? (The answers are some of the nucleotides found in DNA)

adenine, guanine

Which of the following is a byproduct of photosynthesis that is used during cellular respiration? oxygen NADH carbon dioxide ATP FADH2

oxygen

Which of the following are found in all DNA nucleotides? ribose sugar uracil phosphate nitrogen-containing base

phosphate, nitrogen-containing base

Photosystems I & II consist of a ______ complex and an electron acceptor.

pigment