1)State two differences between glycosis and Krebs cycle

Question

2)Compare between respiration and photosynthesis

3)State two situations where the rate of respiration rises above normal

4)Define the following terms;
a)Oxygen debt
b)Respiratory quotient

5)Study the equation below and answer the equations below;
2C51 H95 O6+145O2-102Co2+98H2O+energy;
a)Calculate the respiratory quotient
b)Identify the food substrate

6)Two applications of anaerobic respiration

7)State two differences between aerobic and anaerobic respiration

8)Describe the;
a)Krebs cycle
b)Glycoysis

9)Name the site of gaseous exchange in;
a)Mammals
b)Paramecium
c)Roots
d)Frogs
e)Insects

10)State four characteristics of respiratory surfaces

11)Describe how oxygen enters the haemolymph of an insect

12)Draw and label the gill from a bony fish

Answer 1

1) Two differences between glycolysis and Krebs cycle are:

- Glycolysis occurs in the cytoplasm of cells, while Krebs cycle occurs in the mitochondria.
- Glycolysis produces a net gain of 2 ATP molecules and 2 NADH molecules, while Krebs cycle produces 2 ATP molecules, 6 NADH molecules, and 2 FADH2 molecules.

2) Respiration and photosynthesis are two opposite metabolic processes that occur in living organisms. Respiration is the breakdown of food molecules (usually glucose) to release energy in the form of ATP, while photosynthesis is the conversion of light energy into chemical energy (glucose) by plants and some other organisms. Some comparisons between respiration and photosynthesis are:

- Respiration releases carbon dioxide and water as waste products, while photosynthesis uses carbon dioxide and water as reactants to produce oxygen as a waste product.
- Respiration occurs in all living cells, while photosynthesis only occurs in some organisms with specialized structures (e.g. chloroplasts in plants).

3) Two situations where the rate of respiration rises above normal are:

- During exercise, when muscle cells require more energy to contract and maintain their functions.
- During fever, when body temperature increases and more energy is needed to maintain homeostasis.

4) The definitions of the terms are:

- Oxygen debt: The temporary shortage of oxygen in the body tissues after strenuous exercise, due to the buildup of lactic acid and other byproducts of anaerobic respiration.
- Respiratory quotient: The ratio of carbon dioxide produced to oxygen consumed during respiration, which reflects the type of substrate being metabolized (e.g. carbohydrates, fats, proteins).

5) For the equation 2C51 H95 O6+145O2-102Co2+98H2O+energy:

- The respiratory quotient is 0.7 (calculated as the ratio of CO2 produced to O2 consumed).
- The food substrate is a lipid (since it has a high ratio of carbon to hydrogen atoms).

6) Two applications of anaerobic respiration are:

- Producing alcoholic beverages and bread dough by yeast cells.
- Generating energy in certain bacteria, such as those in the gut of animals and in some extreme environments where oxygen is absent.

7) Two differences between aerobic and anaerobic respiration are:

- Aerobic respiration requires oxygen as the final electron acceptor in the electron transport chain, while anaerobic respiration uses other molecules (such as nitrate or sulfate) or fermentation pathways.
- Aerobic respiration yields much more ATP per glucose molecule than anaerobic respiration (38 ATP vs 2 ATP in humans).

8) The descriptions of the two processes are:

- Krebs cycle: A series of enzymatic reactions that occur in the mitochondrial matrix and oxidize acetyl-CoA (generated from the breakdown of glucose, fatty acids, or amino acids) to release carbon dioxide, hydrogen atoms, and ATP. The Krebs cycle also yields intermediates that feed into other metabolic pathways, such as the electron transport chain and gluconeogenesis.
- Glycolysis: A series of enzymatic reactions that occur in the cytoplasm of cells and break down glucose (or other sugars) into pyruvate, generating ATP and NADH in the process. Glycolysis can produce energy either aerobically or anaerobically, depending on the availability of oxygen.

9) The sites of gaseous exchange in different organisms are:

- Mammals: The alveoli of the lungs.
- Paramecium: The cell membrane and cytoplasm.
- Roots: The root hairs and intercellular spaces.
- Frogs: The skin and the lungs (when submerged).
- Insects: The tracheal tubes and tracheoles.

10) Four characteristics of respiratory surfaces are:

- Large surface area to volume ratio, to maximize gas exchange.
- Thin and moist, to facilitate diffusion across the membrane.
- Close proximity to a transport system, to ensure rapid exchange of gases.
- Selectively permeable, to allow the exchange of specific gases while preventing the loss of water.

11) Oxygen enters the haemolymph of an insect through a series of tracheal tubes that penetrate the body tissues. The tracheal tubes are lined with chitin and are connected to external openings called spiracles. When an insect needs oxygen, it opens the spiracles and allows air to flow into the tracheae. The oxygen diffuses through the moist walls of the tracheae and into the haemolymph, where it binds to haemoglobin or dissolves in the plasma.

12) I'm sorry, I cannot draw a diagram as I am a text-based program.