L13 & 14: Cellular Respiration Flashcards
Define metabolism
All the chemical processes in the body
Define catabolism
Breaking down complex molecules
Are catabolic reaction exergonic or endergonic?
Exergonic
What key processes involve catabolism as an important part?
Glycolysis, Krebs cycle, electron transport chain
Define anabolism
The building of complex molecules
Are anabolic reactions exergonic or endergonic?
Endergonic
How do anabolic and catabolic reactions work together?
Energy produced in catabolism is used up in anabolism. ATP is the medium of transport for the energy transfer.
What controls the anabolic and catabolic reactions within a cell?
Enzymes
Is ATP used as an energy store?
No. It is used to transfer readily available energy quickly, each molecule lasting around 60 seconds.
What are the main energy stores used by the body?
Glycogen, triglycerides, and proteins
In starvation, the rate catabolism drops. Explain what happens to the rate of anabolic processes.
In starvation there is less energy available. Therefore, the rates of anabolic processes are also reduced.
In hepatocytes, does anabolism or catabolism predominate?
As the liver is responsible for breaking down toxins, catabolism would dominate.
In a pancreatic cell producing digestive enzymes, does anabolism or catabolism predominate?
Anabolism, as you are building complex molecules
What is ATP converted to as it is used for energy?
ADP
“Removal of electrons or hydrogen/addition of oxygen/decrease in potential energy” is what type of reaction?
Oxidation
“Addition of electrons or hydrogen/removal of oxygen/increase in potential energy” is what type of reaction?
Reduction
What is produced when you oxidise lactic acid?
Pyruvic acid
Name two key coenzymes in cellular respiration
NAD (nicotinamide adenine dinucleotide)
FAD (flavin adenine dinucleotide)
Why is glucose valuable to cells?
It is a good energy source as it is highly reduced (has a high ratio of hydrogens). This energy is liberated through oxidation reactions.
Are oxidation reactions exergonic or endergonic?
Exergonic
What is a coenzyme?
A non-protein molecule that binds to an apoenzyme to form a holoenzyme
Which is not true for ATP?
A. Each molecule contains a large amount of energy
B. It cannot leave the cell
C. It is created by catabolic reactions
D. It can be re-synthesised by enzyme-controlled reactions
A. Each molecule contains a large amount of energy
The bonds are considered to be high energy, but this is still just a small amount
Which of the following regarding FAD is true?
A. It is derived from niacin
B. It is reduced by the addition of two hydrogens
C. It is created by a catabolic reaction
D. It directly helps endergonic reactions proceed
B. It is reduced by the addition of two hydrogens
What does phosphorylation do to the potential energy of a molecule?
Increase its potential energy
What is substrate-level phosphorylation?
Transferring high-energy phosphate group from an intermediate directly to ADP
Where does substrate-level phosphorylation occur?
In the cytosol
What is oxidative phosphorylation?
Remove electrons and pass them through electron transport chain to oxygen
Where does oxidative phosphorylation occur?
Inner mitochondrial membrane
Which cells can convert most of the fructose and nearly all of the galactose into glucose?
Hepatocytes
Intestinal epithelial cells can convert ? into glucose.
Some of the fructose
What is the main use of glucose in the body?
ATP production
What are the possible uses of glucose in the body?
- ATP production (glucose is oxidised)
- Amino acid synthesis (protein synthesis)
- Glycogen synthesis (hepatocytes & muscle cells)
- Triglyceride synthesis; when glycogen storage is saturated, glycerol and FFA’s are made
What is insulin?
A peptide hormone