Unit 3.3 Flashcards
Annotate a diagram of the ultrastructure of a generalized animal cell
The diagram should show
ribosomes, rough endoplasmic
reticulum, lysosomes, Golgi
apparatus, mitochondria and
nucleus.
Annotate a diagram of the ultrastructure
of a mitochondrion
Cristae, inner matrix and outer
smooth membrane
Define the term cell respiration
Cell respiration is the controlled
release of energy in the form of ATP
from organic compounds in cells
Explain how adenosine can gain and lose
a phosphate molecule
When energy is released from ATP, a phosphate molecule is lost
- From ATP (Adenosine Triphosphate) to ADP (Adenosine Diphosphate)
- When ATP is resynthesized using the energy given off from Creatine Phosphate, a
phosphate molecule is gained. - From ADP (Adenosine Diphosphate) to ATP (Adenosine Triphosphate)
Explain the role of ATP in muscle contraction
From ATP (Adenosine Triphosphate), broken by ATPase:
To ADP (Adenosine Diphosphate) + P (Phosphate) + Energy:
ATP is broken down into ADP, during this process, the bond between the phosphate
molecules releases energy.
- This energy is used for muscle contraction
- As ATP stores are low in our bodies, it has to be re-synthesized to allow us to keep
exercising
Describe the re-synthesis of ATP by the ATP-PC system
Phosphocreatine System (ATP-PC)
- Anaerobic Reaction
- Occurs in the cytoplasm of the muscle cells
- Produces 1 ATP
- ATP is resynthesized very quickly
1.Creatine phosphate has a high energy bond that’s broken by creatine kinase
2. This energy is used to resynthesize 1 molecule of ATP
3. The phosphate that is separated from the creatine phosphate and the energy that is
created, goes into the ADP to create ATP
4. Therefore, ADP gains 1 phosphate molecule by using the energy, creating ATP
5. ATP is then broken down with the help of ATPase, and the energy from the broken
bond is released and used for exercise
Advantages of ATP by the ATP-PC system
Advantage
it can produce energy quickly since no
oxygen is required
Disadvantage:
only lasts a 1-2 seconds
- Describe the production of ATP by the lactic acid system
Lactic Acid System (Anaerobic Glycolysis)
- Anaerobic Reaction
- Occurs in the cytoplasm of the muscle cells
- Produces 2 ATPs
- ATP is resynthesized quickly
Steps:
1. Glucose is broken down by glycolysis into pyruvate, giving off energy (2 ATPs)
2. Since oxygen is not present, the pyruvic acid is converted to lactic acid
3. Lactic acid is the by-product, and it leads to an increase in hydrogen ions
- lactic acid accumulates in our cells and the acidity causes fatigue
4. In order to get rid of the lactic acid, you must breathe aerobically, to pay back the
oxygen debt
5. The oxygen will remove the lactic acid and change it back to pyruvate
Advantages Disadvantages lactic acid system
-it can produce energy quickly since no
oxygen is required
Disadvantages
- cells become more acidic leading to fatigue
- it can only provide energy for 30 sec - 2 min
Describe the production of ATP from glucose and fatty acids by the aerobic system
Aerobic Reaction
- Occurs in the matrix and in the cristae of the mitochondria
- Produces 36-38 ATPs
- ATP is resynthesized slowly
Glucose is broken down by glycolysis into pyruvate
2. Since oxygen is present, the pyruvate produced is converted to Acetyl CoA
3. It enters the aerobic system (Krebs Cycle and Electron Transport Chain)
Krebs Cycle:
- Happens in the matrix of the mitochondria
- This process produces around 2 ATPs
This is where Acetyl CoA is converted into:
a. Water
b. Carbon dioxide
c. Hydrogen (used in the ETC)
Electron Transport Chain (ETC):
- Happens in the cristae of the mitochondria
- This process produces around 32-34 ATPs
The hydrogen produced in the Krebs Cycle is:
- Split into hydrogen ions and electrons, these are charged with energy
- The hydrogen ions combine with oxygen to create water
- The electrons provide the energy to resynthesize the ATP
The aerobic energy system can not only break down glucose, but it can also break down fats
and proteins
Advantages
- it can last for a few hours
Disadvantages
- relies on oxygen consumption
Describe the production of ATP from beta oxidation
fatty acids are broken down by beta oxidation;
catabolized into acetyl CoA;
acetyl CoA enters the Krebs cycle;
electrons are released from the Krebs cycle and beta oxidation into the electron transport chain;
produces triple the amount of glycogen / 100–150 ATP;
waste products are CO2 and water;
Explain the phenomena of oxygen deficit and oxygen debt
When we start to exercise, not enough O2 can be supplied to meet the demands. We have to respire anaerobically (oxygen deficit)
After 2-3 minutes, we start to respire aerobically, and can meet the oxygen demand (amount of oxygen required during exercise)
After we stop exercising, we continue breathing hard to pay back the deficit (debt), and amount of oxygen that needs to be consumed after exercise to repay the deficit that was built up during exercise (epoc)
Resting o2 consumption is amount of oxygen consumed before exercise
Oxygen Deficit
the amount of oxygen required during exercise
Oxygen Debt-
the amount of oxygen that needs to be repaid after vigorous exercise aka
EPOC (Excess Post-Exercise Oxygen Consumption)
How does EPOC Help?
(slow component):
Removal of lactic acid from muscles and blood
Maintenance of body temperature and
ventilation
(fast/rapid component):
Resynthesize muscle stores of ATP-PC
- Takes 3-4 min for stores to fully recover
Replenishment of myoglobin stores with
oxygen
