Human Cells Unit 1 KA 7 Flashcards
Cellular Respiration
What is Cellular respiration?
Cellular respiration is a series of metabolic pathways that releases energy from food and generates ATP
What is ATP composed of?
ATP is composed of adenosine and three inorganic phosphate (Pi) groups
When is energy released from ATP?
Energy is released from ATP when the bond attached to the terminal phosphate is broken by enzyme action
What is formed when ATP breaks down and releases energy?
When ATP is broken down and releases energy, it forms ADP and inorganic phosphate (Pi)
What is Phosphorylation?
ADP + Pi -> ATP
Why is ATP important?
ATP is important as it acts like a link between catabolic and anabolic reactions
(Catabolic - releases energy) (Anabolic - consumes energy)
Why do humans not require a vast store of ATP?
Humans do not require a vast store of ATP as it is continously made at the same time as being used up
What are the three stages involved in Cellular Respiration?
1) Glycolysis
2) Citric Acid Cycle
3) Electron Transport Chain
Where does Glycolysis occur?
(Stage 1/3)
Glycolysis occurs in the cytoplasm
Where does the Citric acid cycle occur?
(Stage 2/3)
The citric acid cycle occurs in the central matrix of the mitochondria
Where does the Electron transport chain occur?
The elctron transport chain occurs in the inner membrane of the mitochondria
What is Glycolysis?
Glycolysis is the breakdown of glucose into two pyruvate molecules
Glucose -> 2 Pyruvate
How much ATP is produced in the energy payoff phase of Glycolysis?
What is the net gain per glucose molecule?
4 ATP are produced in the energy payoff phase of glycolysis
net gain of 2 ATP per glucose molecule
How much ATP is needed in the energy investment phase of Glycolysis?
2 ATP are needed for the energy investment phase of glycolysis
What enzyme releases hydrogen ions from glucose?
Dehydrogenase enzymes release hydrogen ions from glucose
What happens to the hydrogen ions after being released from glucose?
After being released from glucose, the hydrogen ions are passed onto NAD forming NADH
Glycolysis is an ____ reaction, this means it doesn’t need any ____
(Fill in the blanks)
Glycolysis is an anaerobic reaction, this means it doesn’t need any oxygen
What happens to pyruvate molecules if oxygen is available?
If oxygen is available, pyruvate molecules progress into the citric acid cycle
What happens to pyruvate in the Citric acid cycle?
In the citric acid cycle, pyruvate is broken down to an acetyl group
What happens to the acetyl group in the Citric acid cycle?
In the citric acid cycle, the acetyl group combines with coenzyme A forming acetyl coenzyme A
How is Citrate formed?
Citrate is formed when acetyl from acetyl coenzmye A combines with oxaloacetate
What is released as a by-product of the Citric acid cycle?
Carbon dioxide is a by-produce of the citric acid cycle
How is ATP produced in the Citric acid cycle?
In the citric acid cycle ATP is created as citrate is converted back to oxaloacetate
(regenerated oxaloacetate can then form more citrate)
What happens to the Electrons produced?
The electrons are passed to the Electron transport chain
Which stage of Respiration produces the most ATP?
The electron transport chain produces the most ATP
What is the Electron transport chain?
The electron transport chain is a collection of carrier proteins found on the inner membrane of mitochondria
What does NADH do in the Electron transport chain?
NADH releases hydrogen ions and electrons into the transport chain
What does energy from electrons do in the Electron transport chain?
In the electron transport chain energy from electrons is transferred to proteins in the membrane, providing energy for hydrogen ions to be pumped across the membrane
In the Electron transport chain what does the flow of ions back across the membrane do?
In the electron transport chain the flow of ions back across the membrane synthesises ATP by a protein called ATP synthase
What combines to form water in the Electron transport chain?
In the electron transport chain oxygen, hydrogen, ions and electrons form water
How much ATP is produced per glucose molecule in the Electron transport chain?
In the electron transport chain 38 molecules of ATP are produced per glucose molecule
