Topic 4 Respiration (from 2.34) Flashcards
What is ATP?
‘Energy currency’ of cell - the form in which energy is released
- needed for muscle contraction, active transport, protein synthesis + cell division
What is the function of mitochondria?
- Site of aerobic respiration
2. Release energy
What is the word equations for aerobic respiration?
Oxygen + glucose -> carbon dioxide + water
What is the symbol equation for aerobic respiration?
6O2 + C6 H12 O6 -> 6CO2 + 6H2O
What is the word equation for anaerobic respiration in animals?
Glucose -> lactic acid
What is the word equation for anaerobic respiration in plants?
Glucose -> ethanol + carbon dioxide
When is anaerobic respiration used?
When oxygen is not available/ cannot be supplied fast enough for energy requirement
What happens during anaerobic respiration?
- incomplete breakdown of glucose produces lactic acid in muscles
- after exercise, lactic acid needs to break down into co2 and h2o
- this occurs by reacting lactic acid with oxygen
- > amount of oxygen needed = oxygen debt, which is why there must be a fast supply of highly oxygenated blood to muscles even after exercise
- > explains why heart + breathing rate remain high after vigorous exercise
Why is anaerobic respiration not as useful to cells as aerobic respiration?
- lactic acid is made, build up of this causes pain + muscle fatigue
- less energy released as breakdown of glucose is incomplete
- oxygen debt builds up, as lactic acid must be oxidised into co2 and h2o
Plants + fungi, like yeast, respire anaerobically to release ethanol + carbon dioxide. How is this useful?
Can use ethanol in fermentation to produce alcohol for beer + wine
Can utilise the co2 of yeast to make bread
What colour is hydrogen carbonate indicator in high co2 levels, atmospheric, and low co2 levels?
Yellow
Red
Purple
What are 3 chemicals in cigarettes?
- Nicotine
- Tar
- Carbon monoxide
What is tar?
Carcinogen
What is nicotine and how does it affect the body?
- Increases heart rate
- Narrows blood vessels, leading to increased blood pressure and atherosclerosis
- Addictive
How does carbon monoxide affect the body?
- Binds irreversibly to haemoglobin -> carboxyhaemoglobin - reducing capacity of blood to carry oxygen
- Leads to increase in breathing frequency + depth in order to get to same amount of oxygen into blood
- Circulatory system has to pump blood faster -> increases risk of chd and strokes
Why is lung cancer an effect of smoking?
- Carcinogenic chemicals cause DNA in cells to mutate + divide uncontrollably forming a tumour
- Symptoms include cough, chest pain and coughing blood
What happens to cilia as a result of smoking?
- Cells lining trachea + bronchi produce sticky mucus which traps dirt + bacteria
- Cilia move mucus up and out of lungs
- Heat and chemicals from cigarette smoke paralyse cilia so smokers more likely to get lung infections
Eg bronchitis + emphysema
What is emphysema?
- Walls of alveoli are broken down, elasticity reduced so collapse
- Reduces surface area
- Less gas exchange = reduced oxygen in blood
- Short of breath, coughing, wheezing
What is bronchitis?
- Cilia damaged by smoke + chemicals
- Causes inflammation of bronchi + bronchioles
- Production of mucus by goblet cells in trachea increases but can’t be removed
- Build up of mucus causes infections (traps bacteria)
- Hacking cough, sore throat, headache
Why should you not smoke during pregnancy?
- lack of oxygen given to baby
- affects baby’s growth + development
Investigate the release of carbon dioxide in humans?
- Half fill 2 test tubes w lime water
- Insert rubber bungs
- Two holes in each bung - one connected to capillary tube and the other a t tube that you breathe into (look at diagram in cp book)
The test tube where the t tube is in the lime water will turn cloudy as this is the one you are exhaling into
Investigate the effect of exercise on breathing? CORRMMS
C - intensity of exercise
O- will test on humans of same gender + age who are all moderately active (SSS)
R1- will test range of mild - high intensity exercise
R2- test each three times by doing 15, 30, 45 star jumps in a minute
M1 - count how many breaths test subject takes in minute w stopwatch (m2) after exercising
Explain the effects of exercise on breathing and heart rate
- Heart/breathing rate increases
- > faster transport of glucose + oxygen to muscle cells and removal of carbon dioxide and lactic acid - Arteries supplying muscles dilate -> more blood flow
- Increase sweating -> faster release of heat from body to prevent enzymes denaturing