Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
53 Cards in this Set
- Front
- Back
|
Define cellular respiration
|
the controlled release of energy from organic compunds in cells to form ATP
|
|
|
What happens in anaerobic cellular respiration?
|
pyruvate (from glycolysis) is converted in the cytoplasm to lactate (in humans) or ethanol and carbon dioxide (in yeast) with no further yield of ATP. NADH is oxidized to NAD+ and H+
|
|
|
What happens in aerobic cellular respiration?
|
pyruvate is broken down in the mitochondrion to form carbon dioxide and water with a large yield of ATP
|
|
|
What happens in glycolysis?
|
1 glucose in the cytoplasm is broken down into 2 pyruvate moleucules with a small yield of ATP (2 ATP). (This is a net of 2 ATP; overall 4 ATP were made and 2 were used). NAD+ accepts hydrogen/is reduced to make NADH (2 NADH made in glycolysis).
|
|
|
What happens in the link reaction?
|
pyruvate enters the mitochondrion (active transport, 1ATP per pyruvate used). Each pyruvate is converted to acetyl CoA and one carbon dioxide. One NADH made from NAD+.
|
|
|
What happens in the Krebs cycle?
|
Acetyl groups from acetyl CoA enter the Krebs cycle and the CoA (coenzyme A) is removed and recycled. Acetyl CoA (2 carbons) + oxaloacetate (4 carbons) makes citrate (6 carbons). Citrate/citric acid (6 carbons) breaks down to a 5-carbon sugar, also producing one carbon dioxide and one NADH (from NAD+). The 5-carbon sugar breaks down to a 4-carbon sugar, also producing one carbon dioxide and one NADH (from NAD+). The 4-carbon sugar is rearranged to re-make oxaloacetate; one each of the following is made: ATP, NADH, FADH2.
|
|
|
How many turns of the Krebs cycle are there per glucose?
|
2 (because there are 2 pyruvates made from one glucose)
|
|
|
How many ATP, NADH, and FADH2 are made per one turn of the Krebs cycle?
|
1 ATP, 3 NADH, 1 FADH2
|
|
|
Which is the reduced form of the molecule: NADH or NAD+?
|
NADH
|
|
|
Oxidation or reduction: NAD+ to NADH?
|
reduction
|
|
|
What happens to NADH and FADH2 in aerobic respiration?
|
They are oxidized and give their electrons to the electron transport chain
|
|
|
What happens in the electron transport chain?
|
NADH or FADH2 gives electrons to the ETC. As the electrons are passed from one carrier to another, protons (H+) are pumped from the mitochondrial matrix to the intermembrane space. This results in a high concentration of H+ in the intermembrane space (a proton gradient). The electrons will eventually bond to oxygen, which then combines with other H+ in the matrix to make water. Later, in chemiosmosis and oxidative phosphorylation, the H+ will travel by facilitated diffusion through the ATP synthase (ATPase); as each H+ moves through the ATP synthase one ATP will be made from ADP and inorganic phosphate. 1 NADH lets you make 3 ATP; one FADH2 lets you make 2 ATP.
|
|
|
Explain chemiosmosis as it is used in cellular respiration/explain
|
ATP synthesis is coupled to electron transport and H+ movement. It occurs at the inner mitochondrial membrane, which makes folds called cristae to increase surface area. Electrons are transported through carriers in the electron transport chain; in each step energy is released, which is used to pump protons (H+) across the membrane from the matrix to the intermembrane space. ATP synthase transports H+ from the intermembrane space to the matrix down the concentration gradient; the energy is used to make ATP. (This is achieved when the H+ travels through the ATP synthase (also located in the inner mitochondrial memebrane) to the matrix; as is does do the head of the ATP synthase rotates and the energy that is released allows the phosphorylation of ADP to ATP.
|
|
|
What is oxidation?
|
loss of electrons/gain of oxygen/loss of hydrogen
|
|
|
What is reduction?
|
gain of electrons/loss of oxygen/gain of hydrogen
|
|
|
List the substeps of glycolysis in order
|
phosphorylation, lysis, oxidation, ATP formation
|
|
|
Which way do H+ move in the mitochondria when ATP is being formed?
|
from the mitochondrial matrix to the intermembrane space
|
|
|
In which steps of cellular respiration is ATP made by substrate-level phosphorylation?
|
glycolysis (2), Krebs cycle (1 per turn, 2 total)
|
|
|
In which steps of cellular respiration is ATP made by chemiosmosic/oxidative phosphorylation?
|
electron transport chain
|
|
|
How are aerobic and anaerobic respiration similar?
|
Both start with glucose, do glycolysis, make pyruvate, make ATP, make carbon dioxide (if you are doing alcoholic fermentation)
|
|
|
How are aerobic and anaerobic respiration different?
|
"Anaerobic only: fermentation makes lactic acid in humans, fermentation makes ethanol and carbon dioxide in yeast, recycles NADH to NAD+, occurs in cytoplasm, 2 ATP total. Aerobic only: pyruvate transported to mitochondrion, acetyl CoA made, further oxidized to carbon dioxide and water, makes net of 36 ATP
|
|
|
Explain the relationship between the structures of the mitochondria and their functions.
|
Inner mitochondrial membrane/cristae: highly folded membrane to provide large surface area. This is where ATP synthase and ETC proteins are found. More surface area means more places to do electron transport chain, ATP synthesis, and movement of H+ to the intermembrane space. (The innerward folds of the inner membrane are the cristae). Intermembrane space: the volume is very small, which helps increase the concentration of the protons that are pumped into this area by the ETC. This proton gradient is required for ATP synthesis by oxidative phosphorylation. Matrix: contains the enzymes for the Krebs cycle and parts of the link reaction, allowing it to carry out those functions. Outer membrane: determines which substances enter the mitochondrion. Separates the contents of the mitochondrion from the cell, so you have a specialized compartment to do aerobic respiration. Finally: The mitochondrion has a high surface area to volume ration because it is very small; this makes it good at absorbing pyruvate
|
|
|
Explain how cellular respiration is regulated
|
It is a waste of resources by your body to break down macromolecules cellular respiration if you already have lots of ATP. Your body would rater store the energy as glycogen or fat in case you need it later. Therefore, the body shuts off cell. resp. if you have lots of ATP. ATP inhibits an enzyme called phophofructokinase, which is in glycolysis. (Know this example). This is an example of end-product inhibition, negative inhibition, and allostery.
|
|
|
Why does the absence of oxygen gas cause the cell to do anaerobic respiration?
|
O2 is needed as the final electron acceptor for the electron transport chain. In the absence of oxygen, NADH can no longer be broken down to NAD+ at the ETC because there is no longer anywhere for the electrons to go. Therefore, the cell builds up NADH and runs out of NAD+. NAD+ is a reactant for glycolysis, the link reaction, and the Krebs cycle. Lactic acid/alcoholic fermentation of pyruvate breaks down enough NADH to give you enough NAD+ to keep glycolysis going; however, the amount of NAD+ made in this manner is insufficient to keep the link reaction and Krebs cycle going.
|
|
|
What membrane proteins are found in the inner mitochondrial membrane?
|
carrier proteins for the electron transport chain and ATP synthase
|
|
|
On the mitochondrion diagram, what is 1?
|
inner mitochondrial membrane (the folds are called cristae…must be drawn folded)(you could draw dots on this representing the ATP synthase and the proteins of the ETC)
|
|
|
On the mitochondrion diagram, what is 2?
|
outer mitochondrial membrane
|
|
|
On the mitochondrion diagram, what is 3?
|
mitochondrial matrix
|
|
|
On the mitochondrion diagram, what is 4?
|
intermembrane space (note spelling!)(inner and outer membrane muct me drawn close together so the volume of this is small)
|
|
|
On the mitochondrion diagram, what is 5?
|
DNA naked/circular…like in a prokaryote)
|
|
|
On the mitochondrion diagram, what is 6?
|
ribosomes (70S…like in a prokaryote)
|
|
|
In aerobic cellular respiration, what step comes after glycolysis?
|
link reaction
|
|
|
In anaerobic cellular respiration, what step comes after glycolysis?
|
fermentation (lactic acid fermentation in humans and other animals; alcoholic fermentation in yeast and bacteria)
|
|
|
What step comes after the link reaction?
|
Krebs cycle
|
|
|
What step comes after the Krebs cycle?
|
electron transport chain/oxidative phosphorylation/chemiosmosis & ATP synthesis by ATP synthase
|
|
|
What is the final electron acceptor in cellular respiration?
|
oxygen gas (O2)
|
|
|
How many carbon dioxide are made per turn of the Krebs cycle?
|
2
|
|
|
What is the net amount of ATP made when you ferment glucose to lactate?
|
2
|
|
|
What is the net amount of ATP made when you completely break down glucose to carbon dioxide by aerobic respiration?
|
36
|
|
|
Overall, is cellular respiration oxidation or reduction of glucose?
|
oxidation (remember in the overall formula you are adding 6 oxygen molecules)
|
|
|
Which part of the mitochondrion has the highest H+ concentration?
|
the intermembrane space (#4 on the diagram)
|
|
|
Which part of the mitochondrion has the lowest pH?
|
the intermembrane space (#4 on the diagram). The higher the H+ concentration, the lower/more acidic the pH.
|
|
|
Which steps in cellular respiration have oxygen as a reactant?
|
electron transport chain
|
|
|
Which steps in cellular respiration have carbon dioxide as a product?
|
link reaction, Krebs cycle, alcoholic fermentation
|
|
|
Which steps in cellular respiration have ATP as a product?
|
glycolysis, Krebs cycle, electron transport chain
|
|
|
Which steps in cellular respiration have ATP as a reactant?
|
Glycolysis (in phosphorylation, althogth there is a NET gain of ATP), link reaction
|
|
|
Which steps in cellular respiration have NADH as a product?
|
glycolysis, link reaction, Krebs cycle
|
|
|
Which steps in cellular respiration have NADH as a reactant?
|
electron transport chain, lactic acid fermentation, alcoholic fermentation
|
|
|
Which steps in cellular respiration have FADH2 as a product?
|
Krebs cycle
|
|
|
Which steps in cellular respiration have FADH2 as a reactant?
|
electron transport chain
|
|
|
Which organelle does cellular resipration
|
mitochondria (or mesosomes in prokaryotes) (remember that glycolysis and fermentation happen in the cytoplasm)
|
|
|
How many carbons are in each of the following: glucose, pyruvate, acetyl CoA, oxaloacetate, citrate, carbon dioxide
|
6, 3, 2, 4, 6, 1
|
|
|
What is the first reaction in the Krebs cycle?
|
Oxaloacetate + Acetyl CoA = Citrate + CoA
|
