Exam 2
Which energy pathway connects all living organisms?
Glycolysis
What is the function of the two membranes of mitochondria?
Protons are pumped into the space between the membranes.
The CFTR receptor moves chloride ions out of a cell by active transport. This is an example of
a reaction requiring the input of energy (ATP).
Plants require energy from light to perform photosynthesis in which glucose is formed from carbon dioxide and water. This is an example of
a reaction that takes up energy.
If you were working with a 3D model of an enzyme, and you had found a part representing a molecule that fits into the active site, you would have found something that is
a substrate.
Active transport is different from simple diffusion because active transport
all answers are correct
The region of an enzyme that catalyzes reactions is called
an active site.
Phagocytosis is
an example of endocytosis.
if you measure the air a person has inhaled and exhaled, you will find that the concentrations have ______ in the exhaled air.
lower O2 concentrations and higher CO2 concentrations
Enzymes speed chemical reactions by
lowering the energy required to start a chemical reaction.
In animal cells, the primary organelle that generates molecules of ATP is the
mitochondrion
The Krebs cycle occurs in the
mitochondrion
The electron transport chain occurs in the
mitochondrion
Simple diffusion
moves molecules against a concentration gradient.
animals are
net O2 consumers and CO2 producers.
Plants are
net O2 producers and CO2 consumers.
Noncompetitive inhibition of enzymes
occurs when a substance binds to an enzyme at a site away from the active site.
Competitive inhibition of enzymes
occurs when a substance other than the correct substrate binds at the active site of an enzyme
The diffusion of water across a selectively permeable membrane is
osmosis.
In glycolysis and the Krebs cycle, electrons are removed from glucose and taken up by molecules like NAD+. In such a reaction, glucose is being _____ and NAD+ is being ____.
oxidized, reduced
When electrons are removed from a food molecule, the molecule is
oxidized.
If you were observing mud from the bottom of a pond, you would expect to see glycolysis since it does not require
oxygen
The "spent" electrons from the electron transport chain in aerobic respiration are transferred to
oxygen
A ball at the top of a hill is an example of ______ and a ball rolling down the hill is an example of ______.
potential energy; kinetic energy
Glycolysis of a glucose molecule
produces a net gain of two molecules of ATP
The electron transport chain produces a(n) _____________ gradient.
proton
A variety of carbohydrates, proteins, and fats in a diet
provides many molecules that can enter aerobic respiration at different stages.
The net ATP production in glycolysis is only two because
two molecules of ATP are needed to "activate" glucose.
If a cell contains 95% water in its cytoplasm and the environment surrounding the cell contains 90% water
water will flow out of the cell by osmosis.
In glycolysis, the net number of NADH produced is
2
The theoretical net ATP yield from a molecule of glucose is ______ ATP molecules.
36
The Krebs cycle produces ______, ______, and carbon dioxide.
ATP, electron carriers
Cells use energy for which of the following?
All of the answers are correct.
The chemical formula for glucose is
C6H12O6
The electrons that are transferred during cellular respiration are carried in the molecules
NADH and FADH2.
A cell produces approximately 30 ATP per glucose molecule. However, if you calculated the total energy in a glucose molecule, 90 ATP should be generated. What is the best explanation for this difference?
Some energy is lost as heat.
If you were looking for signs of cellular respiration, you could do tests for the production of
carbon dioxide, water, and ATP.
Examples of potential energy include
chemical bonds and concentration gradients
If asked to point on a diagram of a cell to the place where glycolysis occurs, you would plant to the
cytoplasm.
Cyanide and carbon monoxide block the final step in the electron transport chain. What effect would this have on ATP production in the mitochondria?
decreased ATP, because electrons would not be able to move through the electron transport chain
Entropy is
disorder
Which of the following are examples of potential energy?
electrons in chemical bonds, proton gradient, ATP
Which of the following are examples of kinetic energy?
electrons moving through the electron transport chain, protons moving through ATP synthase
When NaCl (table salt) forms, sodium (Na) loses energy by ______ and chlorine (Cl) gains energy by _____
giving up an electron in oxidation; gaining an electron in reduction
The reactants for cellular respiration are
glucose and oxygen
The three main biochemical pathways of cellular respiration are
glycolysis, Krebs cycle, and electron transport chain.
The only source of ATP production in cells relying fermentation is
glycolysis.
If you radioactively labelled NADH and FADH2, you would observe that the radioactivity would be transported at the
inner mitochondrial membrane.
The main reason that cellular respiration needs to occur step by step is because
it enables cells to harness energy released at each step.
What is the role of oxygen in respiration?
it is reduced at the end of the electron transport chain, forming water.
The energy source that powers photosynthesis is
sunlight
In which case is the energy involved farthest from being kinetic energy?
the energy in chemical bonds
Reduction means
the gain of electrons by an atom or molecule.
Oxidation means
the loss of electrons from an atom or molecule.
Oxidation-reduction reactions
transfer electrons from one molecule to another.
