Biology chapters 3-5
Specifically, what energy source MOST DIRECTLY drives ATP Synthase?
dissipation of a proton gradient
Reactions that require an input of energy are classified as (endergonic/exergonic)? They are typically (anabolic/catabolic)?
endergonic and anabolic
Reactions that require an input of energy are classified as ___________ and they are typically ___________ .
endergonic and anabolic
What types of molecules can cross the phospholipid bilayer of the cell membrane by simple diffusion?
small nonpolar molecules like oxygen and carbon
Describe the meaning of "fluid mosaic"?
structure of the plasma membrane of animal cells
What factors influence enzyme activity?
temperature, pH, substrate concentration, inhibitors
What happens to pyruvate if oxygen is NOT available following glycolysis?
Pyruvate must be fermented
What are the functions of the cytoskeleton?
1) Cell structure 2) Movement of the cell (motility) 3) Cell division 4) Transport of substances within a cell
If 0.9% NaCl solution were isotonic to a cell, then
1.5% would be hypertonic.
What is the energy yield from glycolysis alone?
2 ATP molecules and 2 NADPH molecules, 2 pyruvate molecules
How much ATP is formed during glycolysis?
4 ATP for glycolysis, 1 ATP for citric acid cycle, 30-32 ATP for electron transport system
What is the summary equation for photosynthesis
6CO2 + 6H2O ------> C6H12O6 + 6O2
What MOST DIRECTLY provides energy for ATP Synthase?
A proton gradient
What molecule is the "energy currency" used by living cells?
ATP
What are the products of the "light reactions" in the thylakoid of the chloroplast?
ATP and NADPH
Which of the following are directly or required in the Calvin Cycle to form glucose?
ATP and NADPH and Sunlight
What most directly "feeds" into Citric Acid Cycle?
Acetyl CoA
What are the advantages/disadvantages of anaerobic metabolism
Advantages - Anaerobic is relatively rapid and it does not require oxygen Disadvantages - Anaerobic respiration generates only two ATP's and produces lactic acid
What is the difference between competitive and non competitive inhibition?
Competitive inhibition - inhibitors compete for the "active site" Non competitive inhibition - inhibitor binds to secondary binding site on the enzyme
Which of the following describe functions of the cell membrane and membrane proteins?
Controls movement of all molecules into/out of a cell, detects the change and communicates with neighboring cells, forms the boundary of the cell
Phospholipids arrange themselves into a _____ when placed in water.
Bilayer
What is the summary equation for respiration
C6H12O6 + 6O2 --> 6CO2 + 6H2O
What name is given to the whole set of cyclic reactions that convert carbon dioxide into glucose?
Calvin Cycle
Why must cells be so small?
Cells have to be so small so they can get materials from place to place efficiently. Cells with higher surface area to volume ratio are generally more efficient at obtaining nutrients and getting rid of waste.
Why do plants look green?
Chlorophyll reflects green light
Which TWO of the following are responsible for energy transformations (cellular respiration/photosynthesis)?
Chloroplast and mitochondria
Reactions that release energy are classified as (endergonic/exergonic)? They are typically (anabolic/catabolic)?
Exergonic and catabolic
Compare and contrast facilitated diffusion and active transport pumps.
Facilitated diffusion occurs through the concentration gradient where active transport occurs against the concentration gradient by using energy from ATP.
ATP production in the chloroplast is MOST DIRECTLY driven by glucose.
False
Photosynthesis is driven by green light
False
Photosystem II produces NADPH
False
How does feedback inhibition regulate entire metabolic pathways?
Feedback inhibition - end product of a multi-step pathway "feeds back" to inhibit the first enzyme of the pathway
Enzymes speed up chemical reactions by __________ activation energy.
Lowering
Which organelles act as intracellular digestion centers?
Lysosomes
Does glycolysis require oxygen?
No
What are the components of the endomembrane system?
Nucleus, ER, Golgi, Vesicles, Vacuole, lysosomes, mitochondria
How does osmosis differ from simple diffusion?
Osmosis is the movement of water molecules only and simple diffusion is the movement of some type of solute molecules
What is produced by photosystem II? What is produced by photosystem I?
Photosystem II results in ATP production Photosystem I results in NADPH production
Which of the following organisms can carry out photosynthesis?
Plants, algae and some bacteria (Cyanobacteria)
What is the name of the enzyme that initially "fixes" carbon dioxide?
RuBisCO
During photosynthesis, sunlight is captured and converted into chemical bond energy. However, much of the energy is converted to heat. This heat loss illustrates which law of thermodynamics? First
Second
Compare and contrast simple diffusion and facilitated diffusion. What types of molecules require facilitated diffusion?
Simple diffusion is DIRECTLY through the phospholipid bilayer. Facilitated diffusion is selective on what can pass through. examples of facilitated diffusion are glucose and fructose
What happens to a plant cell when it is placed into a hypertonic solution?
The cell will shrink and lose water through osmosis
What happens to an animal cell when it is placed in a hypotonic solution?
The cell would swell up and explode
Which of the following is NOT true concerning enzymes?
They are unaffected by temperatures
In which area of the cell do the light reactions occur?
Thylakoid Membrane
Specifically, in which part of the chloroplast do the "light reactions" occur?
Thylakoid membranes
Carbon fixation is catalyzed by the enzyme rubisco.
True
How many acetyl CoA molecules are formed per glucose?
Two
Does Glycolysis begin with one molecule of glucose and ends with two molecules of pyruvate.
Yes
do plants have both a mitochondria and chloroplast
Yes
What is a "coupled reaction"? What "energy currency" molecule is often involved in a coupled reaction?
a coupled reaction is a chemical reaction having a common intermediate in which energy is transferred from one side of the reaction to the other. ATP is the energy currency
Which of the following statements is correct regarding the differences between plant and animal cells?
animals do not have a cell wall
What is the difference between kinetic energy and potential energy?
anything that has movement has kinetic energy, potential energy is energy that is being stored
Which of the following is a prokaryotic cell?
bacterium
How do animal cells and plant cells differ?
chloroplasts, the cell wall, and vacuoles.
Where does glycolysis occur?
cytoplasm
State the first and second laws of thermodynamics.
first law - energy may be transferred from place to place or transformed into different forms but it cannot be created or destroyed Second law - all energy transfers and transformations are never completely efficient, in every energy transfer some amount of energy is lost in a form that is unusable
Compared with a eukaryotic cell, a prokaryotic cell
lacks organelles beyond ribosomes
What do enzymes do?
lower activation energy
Glycolysis begins with one molecule of _______ and ends with two molecules of _______
one molecule of glucose and two pyruvates
What types of organisms can carry out photosynthesis?
plants, algae and cyanobacteria
What features do all cells have in common?
plasma membrane, cytoplasm, ribosomes, DNA
If oxygen is available, what happens to pyruvate?
progress into the citric acid cycle
What is the function of ribosomes?
protein synthesis
What are the functions of the cell membrane?
semi permeable layer that surrounds every living cell
How do enzymes do it?
shape determines function of the enzyme
What are the types of cell to cell junctions?
tight junctions (forms a waterproof barrier), desmosomes (keeps neighboring cells attached to each other) gap junctions (allows very specific molecules to move between neighboring cells)
What is "simple diffusion"?
when molecules spread from an area of high to an area of low concentration
What is the nucleolus?
where ribosomes are made