Yr 11 - SCB - B2.4 - Respiration

Question 1

Purpose of respiration

Answer 1

process by which cells in plants and animals break down sugar and turn it into energy, which is then used to perform work at the cellular level

Question 2

Mitochondria function and adaptations

Answer 2

The outer membrane covers the organelle and contains it like a skin. The inner membrane folds over many times and creates layered structures called cristae. This increases surface area and allows for more reactions. The fluid contained in the mitochondria is called the matrix.

Question 3

Specific num of mitochondria.

Answer 3

Red blood have no mitochondria

Skin cells have a couple of hundred
Liver cells contain around 1000

The heart muscle contains 5000+

Variation in number is related to the energy requirements of the particular cells. The higher the energy demand, the greater the number of mitochondria.

Question 4

Stages of respiration

Answer 4

1. Glycolysis
   - occurs in the cytoplasm
   - changes glucose into pyruvate which goes to stage 2 if completing aerobic respiration
   - 4 ATP produced (2 used)
2. Krebs cycle
   - occurs in the matrix of the mitochondria
   - pyruvate is reacted with oxygen to release CO2 and and H+ ions
   - CO2 diffuses and H+ ions enter stage 3
   - 4 ATP produced (2 used)
3. Electron transport chain
   - occurs in crystal of mitochondria
   - hydrogen ions are passed along chain releasing energy
   - oxygen is required and water is produced
   - 38 ATP released (2 used)

Question 5

factors that effect respiration

Answer 5

• temperature
• cell energy demands
  Enzyme factors:
• temp/ph
• concentration pf substance
• enzyme concentration
• co enzymes and cofactors

Question 6

word equation for aerobic respiration

Answer 6

Glucose + Oxygen → Carbon dioxide+ Water+ ATP

Question 7

word equation for ANaerobic respiration

Answer 7

Glucose →Lactic acid + ATP