Ch. 7 Bio
Acetyl-CoA molecules are available for the Krebs cycle after lipids have undergone ______.
beta-oxidation
Fatty acid tails of lipids are broken down two carbons at a time in a process called ______.
beta-oxidation
The large amount of energy in lipid molecules is made available for cellular respiration when a process called ______ breaks down the long fatty acid tails into ______ molecules that are able to enter the Krebs cycle.
beta-oxidation; acetyl-CoA
Food molecules lose electrons to obtain energy that is used to make ATP during a process called ____
cellular respiration
The process by which electrons are stripped from organic molecules in order to manufacture ATP is known as ______.
cellular respiration
ATP is produced after the electron transport chain by ______.
chemiosmosis
After proteins are broken down into amino acids, the next step is the removal of the nitrogen side group in a process called ______, which results in the conversion of the amino acids into molecules that are able to enter ______.
deamination; the Krebs cycle
The metabolic pathway in which electrons and hydrogen atoms from NADH are donated to an organic molecule and not the electron transport chain is called ______.
fermentation
In the absence of oxygen, a pathway called ______ is needed to recycle NAD+ so that the anaerobic, ATP-generating pathway called ______ can continue.
fermentation; glycolysis
In most eukaryotes, what food molecule is broken down to produce ATP during cellular respiration?
glucose
During cellular respiration, electrons are harvested from the chemical bonds of ______, and their energy is used to produce ______.
glucose; ATP
The first stage of cellular respiration occurs in the cytoplasm and is called ______.
glycolysis
During ______, two three-carbon molecules of pyruvate are produced from a six-carbon glucose molecule, and ______ results in the production of 2 ATP molecules.
glycolysis; substrate-level phosphorylation
The electron transport chain of aerobic cellular respiration is located in the ______.
inner mitochondrial membrane
The electron transport chain is located in the ______, and the energy from electrons is used to pump protons into the ______.
inner mitochondrial membrane; intermembrane space
In the electron transport chain, the third protein complex is not only a proton pump but also ______.
links oxygen and hydrogen atoms to form water
The Krebs cycle and the electron transport chain of oxidative respiration take place in the matrix of an organelle called a
mitochondrion
NADH and FADH2 produced during the first stages of cellular respiration carry electrons to the electron transport chain, which consists of ______.
molecules associated with the inner mitochondrial membrane
As organic molecules are broken down, electrons are lost from atoms during a process known as ______.
oxidation
The loss of an electron from an atom or molecule is called
oxidation
Before it enters the Krebs cycle, pyruvate is ______.
oxidized to form acetyl-CoA
At the end of the electron transport chain what acts as the final electron acceptor?
oxygen
Even though glycolysis yields only 2 ATP, it is the only way organisms can get energy from food when ______.
oxygen is absent
During substrate-level ______, a high-energy phosphate is removed from a substrate and added to ADP.
phosphorylation
The protein complexes in the electron transport chain all use the energy of electrons to ______.
pump protons into the intermembrane space
Acetyl-CoA is produced by the oxidation of ______.
pyruvate
What product of glycolysis will be oxidized to acetyl-CoA, which can then enter the Krebs cycle?
pyruvate
What enzyme is responsible for the oxidation of pyruvate to form acetyl-CoA?
pyruvate dehydrogenase
Organic molecules gain electrons through a process called ______.
reduction
The process by which an atom or molecule gains electrons is known as
reduction
The last step of the Krebs cycle is ______.
regeneration of a four-carbon molecule
During the Krebs cycle, a six-carbon molecule is oxidized to become first a five-carbon molecule, and then a four-carbon molecule. Where do the lost carbons go?
released as CO2
Energy is obtained from carbohydrates after they are broken down into ______.
simple sugars
During glycolysis, ATP is synthesized by a process called ______, in which a high energy phosphate group is transferred from a substrate to ADP.
substrate-level phosphorylation
Deamination reactions remove nitrogen side groups from amino acids, which are then converted into molecules that can enter what stage of cellular respiration?
the Krebs cycle
Two-carbon fragments pulled from fatty acids are attached to coenzyme A to form acetyl-CoA that can enter ______.
the Krebs cycle
Acetyl-CoA produced from pyruvate enters a series of reactions called ______, which takes place in the ______.
the Krebs cycle; mitochondrion
During aerobic cellular respiration, oxygen accepts electrons at the end of ______.
the electron transport chain
In aerobic respiration, ______ consists of protein complexes and other carrier molecules associated with the inner mitochondrial membrane.
the electron transport chain
What is a step in ethanol fermentation?
the removal of a CO2 from pyruvate
The energy released by the electron transport chain is used to ______.
transfer protons into the intermembrane space
During cellular respiration, NADH and FADH2 act to ______.
transport electrons to the electron transport chain
Eukaryotic organisms that carry out ethanol fermentation are ______.
yeasts
Single-celled fungi called ____ are able to carry out ethanol fermentation that is important in the production of bread, wine, and beer.
yeasts
Select all of the following that are directly involved with the chemiosmotic production of ATP during the electron transport chain.
- ATP synthase - proton gradient
Select all the reactants for cellular respiration.
- C6H12O6 - oxygen
Select all of the following that are end products of ethanol fermentation.
- CO2 - NAD+ - ethanol
Select all of the following that are true about fermentation.
- Glycolysis can continue to produce a small amount of ATP if NAD+ is available. - During fermentation, NADH is recycled to NAD+. - Fermentation produces ATP. - Fermentation can take place in the absence of oxygen.
Select all the molecules that carry electrons used to the electron transport chain of cellular respiration.
- NADH - FADH2
Select all of the following that apply to the first stage of cellular respiration.
- called glycolysis - anaerobic - occurs in the cytoplasm
Select all the processes involved in cellular respiration.
- glycolysis - the Krebs cycle - an electron transport chain
Select all of the following that are true about pyruvate dehydrogenase.
- removes CO2 from pyruvate - one of the largest enzymes known - adds coenzyme A to a two-carbon fragment
Depending on the energy needs of the cell, acetyl-CoA molecules can be used for which of the following? Select all that apply.
- the Krebs cycle - fat synthesis
The passage of one molecule of glucose through glycolysis, the oxidation of pyruvate, and the Krebs cycle produces ______ molecules of NADH, ______ molecules of FADH2, and ______ molecules of ATP.
10; 2; 4
During glycolysis, what is the net number of ATP molecules made per molecule of glucose?
2
The early reactions of glycolysis require an input of ______ ATP molecules.
2
C6H12O6 --> 6CO2 + 6H2O + ATP. Choose the reactant missing from the equation for cellular respiration.
6O2
What occurs during glycolysis?
A six-carbon sugar is broken into 2 three-carbon molecules.
Phosphates obtained from two molecules of ______ are added to glucose in the first few steps of glycolysis.
ATP
During chemiosmosis, the proton channel on the inner mitochondrial membrane that is used to add a phosphate to ADP is called ____ ____
ATP synthase
The movement of protons back into the mitochondrial matrix allows for the formation of ATP using a special proton channel called ______.
ATP synthase
What describes fermentation?
An organic molecule is reduced while NADH is oxidized.
In order for acetyl-CoA to be produced from a pyruvate molecule, what must occur?
CO2 must be lost from the pyruvate molecule.
True or false: Glycolysis likely evolved after oxygen was present in the Earth's atmosphere.
False
Which part of oxidative respiration produces CO2, ATP, NADH, and FADH2 molecules?
Krebs cycle
After glycolysis, pyruvate is oxidized to form ______, which enters the Krebs cycle if the cell needs ATP.
acetyl-CoA
The Krebs cycle begins when ______ enters the cycle and binds to a four-carbon sugar.
acetyl-CoA