1Describe the structure of ATP.
Type of nucleotide - adenine base ribose sugar and 3 phosphate groups(draw it)
2Outline properties of ATP that make it suitable for the use as an energy currency within cells.
There are high energy bonds between the three phosphates. The bond between the last two phosphates is unstable, and when broken releases energy which can be used as activation energy for metabolic chemical reactions.
3Outline example cellular processes that require use of ATP.
synthesis of macromolecules:
ATP supplies energy for condensation reactions, such as protein or nucleic acid synthesis
4Describe the ATP-ADP cycle, including the relative amount of energy and the roles of hydrolysis and phosphorylation.
The hydrolysis of ATP to ADP (Adenosine diphosphate) and an inorganic phosphate (Pi) releases energy that is used as activation energy for metabolic reactions. The regeneration of ATP from ADP and Pi by condensation reactions(phosphorilation) require energy. Cellular respiration provides the energy for the regeneration of ATP.
5State why heat is generated during the ATP-ADP cycle.
energy transfers during into conversions are not 100% efficient - ATP spontaneously dissociates into ADP + Pi, and the free energy released during this process is lost as heat.
6Define cellular respiration.
Process that releases energy by breaking down and oxidising glucose and other food molecules in the presence of oxygen
7Distinguish between cellular respiration and gas exchange.
Gas Exchange (respiration) is the movement of oxygen form the inhaled air into the blood and carbon dioxide from the blood into the air to be exhaled.
cellular respiration involves the oxidation of carbon compounds to release energy. Respiration is the controlled release of ATP energy from organic compounds (food) within cells.
8List reasons why cellular respiration must be continuously performed by all cells.
ATP can not be stored for later use.
ATP can not be transferred from cell to cell.
When ATP is used in cells, heat energy is released. This heat energy can not be reused and will be lost to the environment.
9List common substrates of cellular respiration.
Humans: glucose and fatty acids ( food we eat )
Plants: carbohydrates or lipids made by photosynthesis
10Compare anaerobic fermentation and aerobic respiration.
Aerobic and anaerobic respiration are vital metabolic processes in human
Both occur within cells, utilizing glucose as the initial substrate
11 contrast anaerobic fermentation and aerobic respiration.
anaerobic
doesn't require oxygen
Produces lactate or ethanol as a waste product.(creating oxygen debt)
It takes place in the cytoplasm
Net gain: 2 ATP
aerobic
breaks down glucose with oxygen(glucose + oxygen -> Energy(ATP) + Water + carbon dioxide
It primarily occurs in mitochondria
Net gain: 30 to 34 ATP
12Identify the manipulated (independent), responding (dependent) and controlled variation in experiments of variables affecting the rate of cell respiration.
Independent variable:
- Temperature or pH
Dependent variable:
- Rate of cell respiration (volume of oxygen consumed per unit time)
Controlled variables:
- same conc of substrate
- same pH level
- same duration
- same light exposure
13List three approaches for determining the rate of cellular respiration.
Oxygen uptake
CO2 Production
Consumption of glucose or other respiratory substrates
14Describe three investigative techniques for measuring the effect of a variable on the rate of cellular respiration.
Measure O2 uptake: A capillary tube containing fluid connected to the container to measure changes in the volume of air inside the respirometer
Converting measurements to volumes: Movement of fluid in capillary tube is measured in mm and should be converted to units of volume(fluid will move towards to the tube with the organism)
Calculating rates: Volume of oxygne used must be divided by time. This rate is the dependent variable in an experiment using a respirometer
15Why use potassium hydroxide in respirometers
to absorb co2 allowing oxygen consumption to be messured accuratly