Exam 2
A single "turn" of the Krebs cycle will yield
1 ATP, 3 NADH, and 1 FADH2.
Arrange the following electron acceptors in the proper order in which they participate in electron transport. 1 = Cytochrome c 2 = Oxygen 3 = Cytochrome c oxidase
1, 3, 2
The NET result of a single glycolysis run is the formation of
2 NADH and 2 ATP.
The overall process of glycolysis is responsible for breaking down one glucose molecule into
2 molecules of pyruvate and 2 molecules of ATP.
The initial reaction of the Krebs cycle involves the addition of a
2-carbon molecule to a 4-carbon molecule.
The Calvin cycle starts with a process known as carbon fixation, where ___ carbon dioxide molecule(s) is(are) are "fixed" from a gaseous form to a solid 6-carbon molecule.
3
redox reaction
A chemical reaction involving the transfer of one or more electrons from one reactant to another; also called oxidation-reduction reaction.
Solution?
A solution contains both a solute (Solid), and solvent (liquid)
Movement can cross membrane without Aid of memebrane proteins?
Carbon dioxde gas, glycerol, oxygen gas,lipid soluble molecules,nonpolar molecules
Photosystem I occurs before photosystem II during the light reactions. True or false?
False
The citric acid cycle is responsible for producing the bulk of the ATP generated during cellular respiration. True or False?
False
The formation of ATP as a result of the activity of the electron transport system is termed substrate-level phosphorylation. True or False?
False
The overall goal of the electron transport chain is to break down glucose molecules into pyruvate, producing 2 ATP molecules. True or False?
False
The terminal electron acceptor in the electron transport chain is water. True or False?
False
True or False ? The molecules in a solid lump of sugar do not move.
False
True or False? The reactions that make up cellular respiration occur entirely within the mitochondria of cells.
False
Under aerobic conditions, the end-product of glycolysis is further reduced to yield more ATP. True or False?
False
When oxygen accepts electrons, water is produced as a byproduct. True or False?
False
During the conversion of glucose into a free form of energy only a small percentage is converted into useable ATP. What is the rest of the energy converted into?
Heat
In which of the following ways is photosystem I different than photosystem II?
Photosystem I uses the high-energy electrons to reduce NADP+ to NADPH, whereas photosystem II uses them to convert ADP into ATP.
Chemiosmosis
Process by which a Hydrogen pump pumps protons into the thylakoid membrane. H+ passively flows through the ATP synthase which leads to the creation of ATP.
Which statement is true about the plasma membrane?
Proteins and phospholipids can move sideways within the plane of the membrane.
Internal protein
Proteins that are embedded within the membrane and assist in the transport of materials.
Peripheral protein
Proteins that occur only on the cytoplasmic side of membranes.
function of fermentation
Recyle NADH back to NAD+
The last stage of the Calvin cycle acts to recycle ______, sending it back to aid in _______ again.
RuBP; carbon fixation
Which best describes the second law of thermodynamics?
Some useful energy is lost as heat whenever an energy transfer occurs.
Glycolipid
Sugar chain attach to a phospholipis
Glycoprotein
Sugar chain attach to a protein
The rate of diffusion is affected by which of the following?
Temperature, the size of molecules, and steepness of the concentration gradient
The law of thermodynamics explains?
The laws of thermodynamics explain energy flow and energy conservation and can be applied to biological systems.
If a living plant were moved from a freshwater aquarium to a saltwater aquarium, which of the following would occur?
The plant's cells would lose water and plasmolysis would occur.
Why are plants green?
They reflect green wavelengths of light and absorb blue and red light.
Which of the following is responsible for determining which direction water will diffuse across the plasma membrane of cells?
Tonicity
As the hydrogen ions move down their concentration gradient, energy is released. True or False?
True
Low-density lipoprotein is brought into the cell by receptor-mediated endocytosis. True or False ?
True
The NADH and FADH2 molecules that are used during the reactions of the electron transport chain are derived from glycolysis, the preparatory reactions, and the citric acid cycle. True or False?
True
The energy that is released when hydrogen ions pass through ATP synthase provides the energy needed to form ADP and phosphate from ATP. True or False?
True
True or False? A single "turn" of the Krebs cycle involves three different decarboxylation reactions.
True
True or False? Diffusion is one of the processes whereby materials are exchanged between a cell and its environment.
True
True or False? During glycolysis, a 6-carbon sugar diphosphate molecule is split into two 3-carbon sugar phosphate molecules.
True
True or False? The Krebs cycle occurs in the mitochondrion.
True
True or False? Whenever a molecule is oxidized, another molecule must be reduced.
True
true or false? NADH serves as an electron carrier that can donate its hydrogen to other molecules.
True
non polar
molecules have no dipole, meaning that there is molecular symmetry, which results in no opposing charges.
Proton pumps are protein complexes that
move hydrogen ions across cell membranes.
lactic acid fermentation
occur in mammals
Cells obtain energy by ________ food molecules such as glucose.
oxidizing
What are the end products of photosynthesis?
oxygen and carbohydrate
Certain white blood cells engulf microorganisms and bring them in to digest them. This process is best described as
phagocytosis.
In a phospholipid bilayer, the
phosphate heads are oriented toward the exterior of the cell or toward the cytoplasm.
While we are sitting down to lunch we are consuming _______ energy which will then be converted into ______ energy as we work until dinner time.
potential, kinetic
In glycolysis, glucose is converted to
pyruvate.
The purpose of the preparatory reaction is to break down ________ into ________ so it can enter the citric acid cycle.
pyruvate; acetyl-CoA
The preparatory reaction breaks
pyruvates into acetyl-CoA and carbon dioxide.
Exocytosis is a process by which cells
release substances from the cell via vesicles.
Red blood cells put in a hypertonic solution will
shrivel and become crenated.
potential energy
stored energy ex: The food we eat
Facilitated diffusion is used to transport
sugars and amino acids.
What are require membrane proteins to cross the membrane?
sugars such as starch , polar molcules, ion towards areas of higher concentratrion.
fermentation (anaerobic respiration)
the breakdown of sugars without the use of oxygen, regenerate NAD+ so glycolysis can continue. It turns 2 pyruvate and 2 NADH turns into lactic Acid and NAD
Osmosis can best be described as
the diffusion of water from areas where the water concentration is higher to areas where the water concentration is lower.
When sugar is mixed with water, equilibrium is reached when
the dissolved sugar molecules are evenly distributed throughout the solution.
After high-energy electrons leave photosystem II, they proceed directly to____, where their energy is used to _______.
the electron transport chain; convert ADP into ATP
What is the ultimate destination for the energized electrons during the light reactions of photosynthesis?
they are taken up by NADP+ to produce NADPH
As protons move through the proton pump,
they build up on one side of the membrane, producing a concentration gradient.
The overall goal of the Calvin cycle is to?
use carbon dioxide gas and energy to produce carbohydrates.
Coupling occurs when the energy released by an exergonic reaction is
used to drive an endergonic reaction.
The electrons that are transferred through the electron transport system initially belonged to
NADH and FADH2.
Endergonic reactions
can only occur if there is an input of energy.
reactants of photosynthesis
carbon dioxide and water
Facilitated diffusion requires
carrier proteins
3 types photosynthetic pigment in plants?
chlorphyll a (green) chlorphyll b (green), carateriods (orange/ red)
adhesion junction
connect cells through membrane protein, include desmosomes and hemidesomes, allows for sturdy flexible stretchy cell layers
tight junction
connect cells through membrane proteins, seen in organs whose tissue act as barriers, such as the bladder and bring cells tightly together through a zipperlike fastening.
Where does glycolysis occur?
cytoplasm
Because the reactions aren't cyclic, over time photosystem II would lose all its electrons. This does not happen because?
energy from photosystem I is used to split water molecules, releasing electrons.
kinetic energy
energy of motion ex: rock rolling down a hill or water flowing over a waterfall
If the contents of a beaker are hypotonic in relation to the interior of the cell, water will
enter the cell and lysis will occur.
Red blood cells are also called
erythrocytes
The function of sunlight in photosynthesis is to
excite electrons in chlorophyll
If the contents of a beaker are hypertonic in relation to the interior of the cell, water will
exit the cell and crenation will occur.
If the material the cell takes in is liquid, the process is termed pinocytosis. True or False?
false
extracellular matrix (ECM)
found within animal cell membranes and functions to provide external support and assist in cell to cell comminication.
Reduction
gain of electrons and proton
Product of photosynthesis
glucose and oxygen
is a product of the Calvin Cycle that is used to form glucose phosphate, amino acids or fatty acids.
glyceraldehyde-3-phospate (G3P)
Which of these processes occurs in the cytosol?
glycolysis
Facilitated diffusion occurs
in either direction depending on the concentration gradient of the molecule.
The subunits from which ATP is made are
ADP and phosphate.
The second stage of the Calvin cycle needs an input of energy to reduce the 3PG molecules that resulted from the first stage. Where does this energy input come from?
ATP and NADPH that were supplied through the light reactions
The enzyme responsible for the synthesis of ATP is __________.
ATP synthase
The membrane protein (enzyme) _________ will transform ADP + P Picture ATP as H+ flow down a gradient from the intermembrane space into the matrix.
ATP synthase
product of cellular respiration
ATP, water, carbon dioxide
Phospholipids
Amphipathic molecule with hydrophillic polar head and two hyrophobia non polar tails
Which statement is NOT true about how various conditions will affect the activity of an enzyme?
An enzyme's activity is generally reduced by an increase in substrate concentration.
Factors that affect Enzyme speed activity?
Denaturing the enzyme, Changing the temperature and changing in the PH
Which best describes the first law of thermodynamics?
Energy is not created nor destroyed, but it can change from one energy form to another.
Which of the following is consistent with the laws of thermodynamics governing energy?
Eventually sunlight that is absorbed on the earth returns to space as dispersed heat.
Which statement is NOT true about enzyme inhibition?
In competitive inhibition, the inhibitor binds to the active site of the enzyme. In noncompetitive inhibition, the inhibitor binds to the allosteric site of the enzyme. In irreversible inhibition, a poison binds to the enzyme so that it can never work again. Most inhibitors act in a reversible fashion.
Matrix
Innermost compartment of the mitochondrion. Fluid filled inside space contains enzymes needed for the citric acid cycle and mitochondria.
Which of the following statements about receptor-mediated endocytosis is TRUE?
It involves coated pits.
Which of the following best describes the reduction of the coenzyme NAD?
NAD+ + H -> NADH
If a cell is placed in a hypotonic solution, which will occur?
Water will move into the cell from the surrounding solution.
A photosystem can best be described as
a collection of pigments that trap solar energy and focus it on reaction centers, releasing high-energy electrons.
ATP is considered to be
a molecule that carries a great deal of chemical energy in a chemical bond.
A coenzyme is
a nonprotein organic cofactor that interacts with an enzyme to allow it to work.
A hydrogen atom consists of
a proton and an electron
Under anaerobic conditions, the end-product of glycolysis is converted to
acetic acid.
The first reaction in the citric acid cycle is binding
acetyl-CoA to a C4 molecule.
Before entering the Krebs cycle, pyruvate is converted to
acetyl-CoA.
gap junction
allow for cell to cell comunication, seen in tissues that depends on ion flow,such as within the heart.
alcoholic fermentation
anaerobic process in which cells convert pyruvic acid into carbon dioxide and ethyl alcohol; carried out by many bacteria and fungi such as yeasts
If there are twelve different intermediate products produced in the stages of a metabolic pathway within a cell, we can expect that there
are about twelve enzymes, at least one responsible for each step in the metabolic pathway.
After their generation during the light reactions, NADPH and ATP?
are used in the Calvin cycle reactions to help form carbohydrates.
Red blood cells put in a hypotonic solution will
be destroyed by hemolysis.
If the contents of a beaker are isotonic in relation to the interior of the cell, water will
both enter and exit the cell at equal rates so no net loss or gain occurs.
function of glycolysis
breaks down glucose into to 3 carbon molecules and 2 ATP. 1 glucose molecule is broken into 2 pyruvate molecules.
The movement of protons through ATP synthase occurs from the
intermembrane space to the matrix.
Human erythrocytes function best in a
isotonic solution
Cholesterol
lipids that helps maintain membrane fluidity.
Cytoskeleton filaments
located on the cytoplasmic side of membranes and aid in keeping proteins in place.
Oxidation
loss of electrons and proton
Which of the following is the reason plants wilt if they are watered with a salt solution?
loss of water due to the salt solution resulting in a decrease in turgor pressure
Red blood cells in an isotonic solution are
lozenge shaped.
Cytochromes can best be described as
membrane proteins that house the electron transport chain.
The sum of the chemical reaction in a cell constitute
metabolism.
Simple diffusion is defined as the movement of
molecules from areas of higher concentration to areas of lower concentration.
