ER Flashcards
What is the primary need for energy in living organisms?
To support anabolic reactions, cellular work, movement, and maintenance of body temperature in endotherms
Anabolic reactions include protein synthesis, DNA replication, glycogenesis, and polymerisation.
List examples of anabolic reactions.
- Protein synthesis
- DNA replication
- Glycogenesis
- Polymerisation
These reactions are essential for building complex molecules from simpler ones.
What types of cellular work require energy?
- Active transport
- Movement of chromosomes
- Sliding filaments
- Movement of vesicles
Cellular work is crucial for maintaining cellular functions and processes.
What role does energy play in maintaining body temperature in endotherms?
It is needed for thermoregulation
Endotherms, or warm-blooded animals, rely on metabolic processes to maintain a stable body temperature.
Why is glucose considered stable?
Due to its activation energy
The stability of glucose is important for its role in metabolic processes.
How is the activation energy of glucose lowered?
By enzymes and raising the energy level of glucose through phosphorylation
This process facilitates various biochemical reactions involving glucose.
What type of reactions are involved in the interconversion of ATP and ADP?
Reversible reactions
What leads to energy release in ATP?
Loss of phosphate / hydrolysis
List features of ATP that make it suitable as the universal energy currency.
- Loss of phosphate / hydrolysis leads to energy release
- Small packets of energy
- Small / water-soluble, so can move around cell
- Immediate energy donor
- Acts as link between energy-yielding and energy-requiring reactions
- High turnover
ATP is described as a _______ energy donor.
Immediate
What happens to excess energy during transfer and reactions?
Converted into thermal energy
What are the four stages in aerobic respiration?
Glycolysis, Link reaction, Krebs cycle, Oxidative phosphorylation
Where does glycolysis occur?
Cytoplasm
What is the first step of glycolysis?
Glucose phosphorylated by ATP
What does the phosphorylation of glucose do?
Raises energy level / overcomes activation energy to form fructose bisphosphate
What is produced from the lysis of glucose in glycolysis?
Two TP (triose phosphate)
What is the net gain of ATP produced from glycolysis?
2 ATP
What is produced at the end of glycolysis?
Pyruvate
Where does the link reaction occur?
Mitochondrial matrix
What happens to pyruvate during the link reaction?
Decarboxylation and dehydrogenation
What is formed when pyruvate combines with coenzyme A?
Acetyl coenzyme A
What is the role of coenzyme A in the link reaction?
Combines with acetyl group and delivers it to the Krebs cycle
What does acetyl CoA combine with in the Krebs cycle?
Oxaloacetate
What is produced during the decarboxylation of citrate in the Krebs cycle?
CO2 (waste gas)
How many CO2 are produced in the Krebs cycle?
Two CO2
How many NAD molecules are reduced in the Krebs cycle?
Three NAD molecules
What type of phosphorylation occurs in the Krebs cycle?
Substrate-level phosphorylation
Where does oxidative phosphorylation occur?
Inner mitochondrial membrane
What is released from reduced NAD / FAD during oxidative phosphorylation?
Hydrogen
What happens to electrons in the electron transport chain?
They are passed along electron carriers
What is the role of oxygen in oxidative phosphorylation?
Acts as the final electron acceptor and proton acceptor to form water
What is generated when protons diffuse back through the membrane?
ATP
Fill in the blank: Glycolysis produces _______ and _______.
Pyruvate, 2 ATP
True or False: The Krebs cycle regenerates oxaloacetate.
True
