Cellular respiration Flashcards
What is the end product of cellular respiration?
The production of ATP
What is the function of ATP?
Provides energy for many of the bodies processes such as macromolecule synthesis, cell division, motility (mobility of gametes), transport, signalling etc.
How is the energy from ATP extracted?
By undergoing hydrolysis
Where does ATP come from?
The food we eat
What food sources can ATP come from?
Glucose (main one), amino acids, fatty acids, glycerol
What happens to ATP when you’re active?
It is used to fuel body activities
What happens to small simple molecules (e.g. glucose, amino acids, glycerol, fatty acids) when you’re active?
They are broken down into ATP
What happens to large complex molecules (e.g. glycogen, proteins, triglycerides) when you’re active?
They are broken down into smaller molecules
What happens to ATP when you’re inactive (e.g. sleeping)?
It gets stored in complex molecules as an energy store
How can the energy from food be wasted?
In the forms of heat and nitrogenous waste and faeces
What happens to the energy extracted form cellular respiration?
It is absorbed into the blood stream
Explain the process of extracting food into energy using glucose as an example
Glucose is energy extracted from food, it is then absorbed into the blood stream. Glucose is then absorbed by a cell with the help o insulin where it is either used for cellular respiration (ATP production) or stored for later times (glycogen production)
What regulates the release of energy from glycogen?
Glucagon
What are the three major biochemical pathways for energy extraction?
Glycolysis, Krebs cycle and electron transport and chemiosmosis
What process enables blood sugar levels to be controlled?
Homeostasis
What is the normal blood glucose levels?
70-110mg/dL
What happens when blood sugars fall below normal levels?
Alpha cells in the pancreas secrete glucagon. This increases breakdown of glycogen into glucose (glycogen stored in liver and skeletal muscle), fatty acids (in adipose tissue) and increased synthesis and release of glucose (in liver)
What happens when bond sugars are above the normal level?
Beta cells secrete insulin. Increases rate of: glucose transport into target cells, rate of glucose utilisation and ATP generation, conversion of glucose into glycogen, amino acid absorption and protein synthesis, triglyceride synthesis in adipose tissue
What is glycolysis?
The anaerobic process that occur in the metabolism to produce ATP
What is the net energy gain from glycolysis per glucose molecule?
1 glucose = 2 ATP
How many reactions are involved in glycolysis? How does this number vary between other organisms?
10, it doesn’t vary very much (indicates that it is perhaps the first metabolic processes to have evolved)
Where does glycolysis occur? What does this mean for the metabolic rate?
In the cytoplasm
It is very easily accessed so it can occur quickly
How does glycolysis produce its energy? What is the energy expenditure and output/waste products?
Harvests energy by oxidising glucose into pyruvate
Produces 2 ATP (by substrate level phosphorylation [adding a phosphate group]) and 2 NADH
Waste produce is pyruvic acid
How does glycolysis link up and start the krebs cycle?
The pyruvic acid is converted into acetyl coenzyme A