bio topic 8 Flashcards
Antifreeze is a compound called ethylene glycol, which is metabolized in mammals to poisonous compounds that cause kidney failure, amongst other symptoms. The first step in metabolism involves an enzyme called alcohol dehydrogenase. Two inhibitors of this enzyme used in treating antifreeze poisoning are ethanol and fomepizole.
Studies have shown that fomepizole may be preferred to ethanol as a treatment. What is a reason for this?
Ethanol is a competitive inhibitor and must be given in very large doses
Succinate dehydrogenase is an enzyme that catalyses the oxidation of succinic acid. If malonic acid is added to the mixture, the rate of reaction is reduced. An increase in succinic acid will increase the rate of reaction again. For this system, which term best describes malonic acid?
Competitive inhibitor
Which statement applies to the tertiary structure of enzymes?
A change in the tertiary structure of an enzyme may result in a change in the structure of the active site.
Which describes the role of amino acids in the channels of membrane proteins used for facilitated diffusion?
Polar amino acids create a channel through which hydrophilic molecules can pass.
The image shows a lady picking tea (Camellia sinensis) leaves. Once the leaves have been picked, all further metabolism must be stopped. By what means could this be accomplished?
Heating
What is an allosteric site?
The area on an enzyme that binds the end-product of a metabolic pathway
What describes non-competitive inhibition?
Inhibiting molecule does not resemble substrate and binds to an area other than active site
Non-competitive inhibitors of enzymes are…
Not resembling the substrate and not binding to the active site
Which part of aerobic respiration directly involves oxygen molecules?
Accepting electrons from the electron transport chain
Which is a reduction reaction?
FAD changing to FADH2
Where does glycolysis happen inside the mitochondria?
It happens outside of the mitochondria, in the cell’s cytoplasm
Where does the electron transport happen in the mitochondria?
Inside the matrix of mitochondria
What term is used for ATP synthesis coupled to electron transport and proton movement?
Chemiosmosis
Where are protons pumped, to allow chemiosmosis in aerobic respiration to occur?
From the matrix of the mitochondrion to the space between the membranes
Where does photolysis happen in the chloroplast?
Thylakoid
Where does carboxylation of RuBP happen in the chloroplast?
Stroma
What does electron tomography allow mitochondria researchers to do?
To produce images of cristae
What happens when pyruvate is converted to acetyl CoA in the link reaction?
Decarboxylation
The following processes occur in aerobic cell respiration.
I. Decarboxylation of pyruvate
II. Diffusion of protons through ATP synthase
III. Phosphorylation of glucose
Which is the correct sequence for these processes?
III -> I -> II
What is phosphorylation?
Phosphorylation of glucose is the first stage in its breakdown and involves the addition of phosphate groups from ATP. This turns the relatively unreactive glucose into a more unstable, phosphorylated compound, which can be split to form two three-carbon sugars
What are the steps in glycolysis?
(PLOA = People Love Outdoor Activities)
1. Phosphorylation - relatively unreactive glucose is activated by reaction with ATP and addition of two phosphate groups
2. Lysis - phosphorylated 6-carbon sugar splits to form two 3-carbon sugar phosphates
3. Oxidation - two NAD+ turn into NADH + H+, energy released as hydrogen acceptor and used to form ATP molecules, two more phosphate groups are added
4. ATP formation - 4 ATP molecules are created together with two 3-carbon sugar-phosphate molecules being converted to two molecules of pyruvate
Which structure in the chloroplast diagram is adapted to carry out chemiosmosis?
Thylakoid membrane
Where does the creation of acetyl CoA occur inside the mitochondria?
Inside the mithochondrial matrix
What happens inside the cristae of mitochondria?
Phosphorylation of ADP
