Disease and Bioenergetics Flashcards
1
Q
What is a communicable disease?
A
An infectious disease caused by pathogens that can be passed from one person to another.
2
Q
What are non-communicable diseases?
A
Diseases that cannot be transmitted from one person to another.
3
Q
What can both communicable and non-communicable diseases cause?
A
ill health
4
Q
What are 3 other factors that can also affect health?
A
Diet, Stress and life situations (environment, gender, ethnic group)
5
Q
What is a pathogen?
A
A microorganisms that cause disease.
6
Q
Name 4 types of pathogen.
A
Bacteria, viruses, protists or fungi
7
Q
Complete the sentence : Communicable diseases are caused either directly by a ____________ or by a ________ made by a pathogen.
A
Pathogen, toxin
8
Q
Give 2 examples of mild communicable diseases.
A
common cold and tonsillitis
9
Q
What are the differences between bacteria and viruses?
A
Bacteria are single-celled living organisms that are much smaller than animal or plant cells.
Viruses are even smaller than bacteria and usually have regular shapes. They can cause disease in every type of living organism.
10
Q
How does bacteria cause disease?
A
They divide rapidly by splitting in to two (binary fission). They can produce toxins that affect your body, making you feel ill. They can also directly damage cells.
11
Q
How do viruses cause disease?
A
Viruses take over the cells of your body. They live and reproduce inside the cells, damaging and destroying them.
12
Q
How are pathogens spread? Give 3 ways.
A
Air (including droplet infection)
Direct contact
Water (contaminated)
13
Q
How do bacteria divide?
A
By binary fission
14
Q
What is a culture medium?
A
A liquid or gel containing nutrients needed to help bacteria grow.
15
Q
What does a culture medium contain?
A
Carbohydrates (energy source), minerals, nitrogen source (to make proteins), sometimes other chemicals
16
Q
How can you prepare an uncontaminated culture of microorganisms in a lab?
A
Step 1:
Sterilise the petri dishes. Glass- autoclave, Plastic- bought sterilised or UV light/Gamma radiation. The nutrient agar must also be sterilised to kill unwanted microorganisms.
Step 2:
Inoculate the sterile agar with the microorganisms you want to grow
Step 3:
Incubate the dishes for several days, stored upside down so condensation doesn’t fall from the lid onto the agar surface.
17
Q
How do you sterilise and inoculating loop?
A
Heat in the blue flame of a bunsen burner
18
Q
How do you sterilise glass petri dishes?
A
In an autoclave
19
Q
What is the maximum temperature at which cultures are incubated in schools? Why?
A
25°C, because higher temperatures means a higher risk of growing harmful pathogens at a faster rate.
20
Q
Why are bacterias incubated at higher temperatures in hospitals?
A
So that human pathogens can grow as fast as possible and are identified sooner
21
Q
The mean division time for a population of bacteria is 30 minutes. Calculate how many bacteria will result from each individual bacterium after 8 hours.
A
2 times/hour
16 times in 8 hours
1x2^16 = 65536
22
Q
What are disinfectants?
A
Chemicals used to kill bacteria in the environment around us.
23
Q
What are antibiotics?
A
Chemicals that can be used inside our bodies to kill bacteria or prevent them from growing.
24
Q
Explain how to investigate the effect of disinfectants and antibiotics. RP
A
- Sterilise a petri dish containing agar gel.
- Add circles of filter paper soaked in different types or concentrations of disinfectant or antibiotic. Add a control disc containing no antibiotic or disinfectant.
- Incubate.
- Measure the zone of inhibition for each paper disc to see its effectiveness. Use πr².
25
Who was Ignaz Semmelweis?
A doctor in the mid 1850s who discovered who diseases were transmitted.
He noticed that when medical students went from dissecting a deceased body to delivering a baby, the woman was more likely to die than if the baby was delivered by a midwife. Semmelweis wondered if they were carrying the disease from the corpses to their patients.
26
What are 5 hygiene measures that can help prevent the spread of diseases?
- Hand washing
- Disinfectant
- Keeping raw meat away from food
- Coughing or sneezing into a tissue rather than hands
- Maintaining the hygiene of people, animals and agricultural machinery to prevent the spread of plant diseases
27
If someone had a serious infectious disease, what should they do?
Isolate
28
What are vectors?
Organisms that carry a disease but are not affected by it
29
What is a vaccine?
A small amount of a dead or inactive pathogen introduced to the body to help prevent disease.
30
Give 2 viral diseases in humans.
Measles and HIV/AIDs
31
What is a viral disease in plants?
Tobacco mosaic virus
32
Give two bacterial diseases in humans.
Salmonella food poisoning, Gonorrhoea
33
What are the symptoms of measles?
fever and red skin rash
34
How is measles spread?
By the inhalation of droplets of coughs or sneezes.
35
What are the symptoms of HIV?
mild, flu-like at first, gradually damages immune system leading to AIDS
36
How is HIV spread?
Direct sexual contact, exchange of body fluids, such as blood, or passed from mother to child in breast milk
37
What are the symptoms of tobacco mosaic virus?
discolouration of leaves and affected growth
38
What is salmonella?
Bacteria that live in the guts of many animals
39
What is gonorrhoea?
A sexually transmitted bacterial disease (STD)
40
What are the symptoms of gonorrhoea?
A thick yellow or green discharge from the vagina or penis and pain on urination.
41
Give an example of a fungal disease in humans.
Athletes foot
42
What can be used to treat fungal diseases in humans?
Antifungal drugs
43
Name a fungal disease in plants.
Rose black spot
44
What are the symptoms of rose black spot disease?
Purple or black spots develop on the leaves. Leaves then turn yellow and drop early, weakening the plant.
45
How are fungal diseases in plants spread?
Carried by the wind and spread over a plant during rainfall.
46
What can be used to treat fungal diseases in plants?
chemical fungicides
47
What is a protist?
A single-celled organisms that usually involve a vector.
48
Name a protist disease in humans.
Malaria
49
What is malaria?
A disease caused by protist pathogens that are parasites - they live and feed on other living organisms.
50
How is malaria spread?
Vector - female Anopheles mosquito
51
True or false : The Malaria protists reproduce asexually in the mosquito.
False - They reproduce sexually in the mosquito and asexually in the human body.
52
How can the spread of malaria be controlled?
- Insecticide mosquito nets
- Using insecticides to kill mosquitoes
- Preventing mosquitoes from breeding (remove standing water/ spray with insecticides)
- Travellers can take anti malaria drugs that kill the parasites if infected
53
Give 5 examples of human defence systems against disease.
Skin - barrier, produces antimicrobial secretions
Nose - hairs, mucus
Trachea and Bronchi - mucus, cilia
Stomach - Acids
Immune system - white blood cells
54
What are three ways that white blood cells protect against disease?
Ingesting microorganisms, Producing antibodies, Producing antitoxins
55
What are aphids?
Insect plant pests that penetrate into the phloem to feed off sugar-rich phloem sap. They damage and weaken the plant.
56
What is chlorosis?
When the level of magnesium ions in the soil is low, the plant cannot make enough chlorophyll causing the leaves to become yellow. Growth slows as photosynthesis cannot take place.
57
What will happen to a plant if there is a nitrate deficiency in the soil?
Growth of plants will be stunted
58
What does stunted growth in a plant indicate?
A nitrate deficiency
59
What do dark spots on leaves indicate?
Black spot fungus
60
What do areas of decay or rotting on plants indicate?
black spot or blights on potatoes
61
What do growths on plants suggest?
Crown galls caused by bacterial infection
62
What is the name of a plant bacterial infection?
Crown gall
63
What do malformed stems and leaves suggest?
Due to aphids or nematode infestation
64
What does discolouration on a plant suggest?
yellowing chlorosis - magnesium deficiency
mosaic patterns - tobacco mosaic virus
65
How can plant diseases be treated?
fungicides, pesticides, fertilisers
66
Give 4 physical barriers that help protect plants from disease?
Cellulose walls - strengthens the plant and helps resist invasion by microorganisms
Tough waxy cuticle - barrier to the entry of pathogens
Bark on trees - protective layer, hard to penetrate
Leaf fall - any infected leaves fall off taking the pathogens with them
67
How do plants protect themselves from herbivores?
Poisons - makes the animal unwell
Thorns - unpleasant to eat
Hairy stems/leaves - painful, deters insects
Drooping or curling when touched- dislodges insects
Mimicry - mimic unhealthy plants or eggs on surface to stop insects from laying actual eggs on surfaces
68
What are antigens?
Proteins on the surface of cells
69
Explain how a vaccine prevents disease.
A small amount of dead or inactive pathogen is introduced to the body. This stimulates the white blood cells to produce the antibodies needed to kill the pathogen to prevent you from becoming ill. Upon reinfection, white blood cells now respond rapidly and make the antibodies as if you had already had the disease, so that you are protected against it.
70
What does the MMR vaccine protect humans against?
measles, mumps and rubella
71
What is herd immunity?
When a large proportion of the population is immune to a disease, the spread of the pathogen in the population is reduced and the disease may disappear.
72
What are antibiotics?
Medicines that work inside the body to kill bacterial pathogens.
73
When did antibiotics first become widely available?
1940s
74
Give an example of an antibiotic.
Penicillin
75
What is penicillin made from?
Penicillin mould/ fungi
76
True or false : Antibiotics kill viral pathogens.
False - they kill bacterial pathogens only.
77
What is the main difference between drugs such as paracetamol and drugs such as penicillin?
Antibiotics cure diseases whereas painkillers only help to relieve pain.
78
How do antibiotics work?
They damage bacterial cells without harming your own cells. They can be ingested or put straight into the bloodstream.
79
Why is it more difficult to develop drugs against viruses than bacteria?
Viruses reproduce inside body cells so it is difficult to kill the virus without damaging the cell.
80
Why are new antibiotics for bacterial diseases in demand?
Some strains of bacterial diseases are becoming antibiotic resistant meaning the antibiotics no longer work on them.
81
What are digoxin, digitalis and aspirin all examples of?
Drugs made from plants
82
What plant does digoxin come from?
foxgloves
83
What is aspirin made from?
Willow bark.
84
Who discovered penicillin?
Alexander Fleming and then Florey and Chain.
85
What are the 4 things that a good medicine is?
effective, safe, stable, successfully taken in and removed from the body
86
What is the first stage of developing a new drug?
Testing in a lab on cells, tissues and organs.
Testing for toxicity and efficacy.
87
What is the second stage of developing a new drug?
Testing on animals to see how they work on whole organisms. Provides information on dosage and side effects.
88
What are preclinical trials?
Testing on cells, tissues and then live animals.
89
What is the third stage of developing a new drug?
Clinical trials - Testing on healthy volunteers and patients. First at very low dosages to check for side effects. If safe, it is tried on a small number of patients to see if it can treat the disease
90
What happens after the optimum dose of a new drug is found in clinical trials?
It must pass legal tests and then is licensed so doctors can prescribe it.
91
What are double blind trails?
A group of patients with the target disease are given a placebo or the new drug. Neither the doctors or the patients know who has received the real drug until the trial is complete. The health of the patients is monitored throughout.
92
What is a placebo?
A medicine that does not contain the drug being tested.
93
What is peer review?
When other scientists working in the same area check over and review results to prevent false claims or bias.
94
What are hybridomas?
Cells produced by combining mice/human cells with cancer cells to be used in medicine.
95
What are monoclonal antibodies?
Proteins that are produced to target particular cells or chemicals in the body.
96
What are lymphocytes?
White blood cells that produce antibodies but cannot divide.
97
Why are tumour cells used in the production of monoclonal antibodies?
They divide rapidly to produce clones of cells.
98
How do scientists produce hybridoma cells?
They combine mice lymphocytes (stimulated to make a particular antibody) with a type of tumour cell.
99
What do single hybridoma cells do to make large amounts of cells that produce the same antibody?
Divides to produce identical cells.
100
What happens after the hybridoma cells divide?
The antibodies are collected and purified and are now monoclonal antibodies.
101
Give the four stages of monoclonal antibody production.
1 - Mice lymphocytes that make specific antibodies but do not divide are combined with tumour cells that don’t make antibodies but divide rapidly
2 - A hybridoma cell is formed
3 - After division, the cells are cloned
4 - monoclonal antibodies are collected and purified to be used
102
How are monoclonal antibodies specific?
The only bind to one site on one specific antigen.
103
Give the 5 ways that monoclonal antibodies can be used.
1 - Pregnancy Tests
2 - Diagnosis of disease
3 - Measuring and monitoring
4 - Research
5 - Treating disease
104
How are monoclonal antibodies used in pregnancy tests?
They bind to the hormone human chlorionic gonadotropin that is made in the early stages of pregnancy. Tiny amounts of the hormone are passed out of the body in urine. Monoclonal antibodies bind to the hormone if it is present and is used to produce the colour change signalling a positive result.
105
What hormone is detected in pregnancy tests by monoclonal antibodies?
Human chlorionic gonadotropin
106
How are monoclonal antibodies used to diagnose a disease?
They are made to bind to specific antigens found on pathogens, blood clots or cancer cells. They carry markers that make it easy for doctors to see where they have built up. This allows doctors to identify and detect problems before seriously affecting a patient’s health.
107
What can monoclonal antibodies measure and monitor?
hormones or chemicals in the blood
108
How do monoclonal antibodies treat disease?
They target a specific type of cell or chemical. They can be used to treat cancer and other diseases.
109
What are the three ways that monoclonal antibodies are used to treat cancer?
1- Direct use of monoclonal antibodies to trigger the immune system to recognise, attack and destroy cancer cells
2 - To block receptors on the surface of cancer cells to stop them from growing and dividing
3 - To carry toxic drugs or radioactive substances or chemicals that stop cancer cells from growing and dividing to attack the cells directly without harming other cells in the body
110
What are the advantages of monoclonal antibodies?
- Only bind to specific antigen
- Healthy cells are not affected
- Can treat a wide range of conditions
- Could become cheaper in the future
111
What are the disadvantages of monoclonal antibodies?
- Not widely used or as successful as hoped
- Created more side effects than expected
- mice lymphocytes could mean rejection in humans
- Difficult to attach to the right drugs
112
Give 3 risk factors for disease.
- Genes
- Age
- Lifestyle
- Gender
- Environment
- Diet
113
What is a casual mechanism?
How one factor influences another through a biological process.
114
Give an example of a casual mechanism.
Smoking tobacco increases the risk of lung cancer
115
What is a correlation?
Similarities in the patterns between non-communicable diseases and lifestyle factors, suggesting a link or relationship between the two.
116
What is a tumour?
When control of the cell cycle is lost and cells grow/divide in an abnormal, uncontrolled way.
117
What type of tumour is non-cancerous?
A benign tumour
118
What type of tumour is non-cancerous?
A benign tumour
119
What is a benign tumour?
Growths of abnormal cells contained in one place, usually within a membrane. They do not invade other parts of the body but can grow large, quickly causing pressure or damage to organs.
120
What do malignant tumour cells do?
spread around the body, invading neighbouring healthy tissues.
121
Give one difference between cancer cells and normal body cells.
Cancer cells divide much quicker and live longer.
122
True or false : Normal cells live longer than cancer cells.
False - cancer cells live longer
123
How are tumour cells spread?
Small clumps of cells are spread by the bloodstream or lymphatic system.
124
Give 4 causes of cancer.
- Genetic risk factors
- Mutations (caused by carcinogens)
- Ionising radiation
- Viral infections
125
Describe how smoking can cause cancer.
Tobacco tar contains carcinogens that cause mutations in genetic material. This leads to cancer
126
What is a carcinogen?
A cancer causing agent
127
How does ionising radiation cause cancer?
They interrupt the normal cell cycle and cause tumours to form.
128
What are two ways that cancer can be treated?
Radiotherapy and Chemotherapy
129
What is radiotherapy?
When cancer cells are destroyed by targeted doses of radiation.
130
How does radiotherapy work?
Targeted doses of radiation stops mitosis in the cancer cells.
131
What is a disadvantage of radiotherapy?
It can damage healthy cells as well as cancer cells.
132
What is chemotherapy?
Where chemicals are used to either stop the cancer cells dividing or make them ‘self-destruct’.
133
What is a secondary tumour?
A tumour created as cells spread to different areas of the body through the blood.
134
What is nicotine?
A harmless but addictive drug found in tobacco smoke.
135
What does nicotine do?
Provides a sensation of calm, well-being and being able to cope.
136
What is carbon monoxide?
A poisonous gas found in tobacco smoke.
137
What does carbon monoxide do?
It takes up some of the oxygen-carrying capacity of your blood leading to a shortage of oxygen.
138
What could happen if a pregnant woman smokes?
Due to carbon monoxide, not enough oxygen can be supplied to the foetus in order for it to grow properly. This could lead to premature births, low weight births or stillbirths.
139
How many babies a year are born dead due to smoking?
700
140
What happens to the cillia of a person that smokes?
They can become anaesthetised and stop working allowing dirt and pathogens into the lungs. Also a build up of mucus results in coughing.
141
What is tar?
A carcinogen. A sticky, black chemical that accumulates in the lungs turning them from pink to grey.
142
What does tar do to the lungs?
Turns them from pink to grey.
143
What is bronchitis?
inflammation and infection of the bronchi
144
What is tar found in?
Tobacco smoke
145
What can the build up of tar in the lungs lead to?
A breakdown in the structure of alveoli, causing chronic obstructive pulmonary disease (COPD)
146
What disease can tar cause?
COPD - Chronic Obstructive Pulmonary Disease
147
How does smoking affect the heart and blood vessels?
- Narrows the blood vessels in skin, causing ageing
- Nicotine increases heart rate
- Chemicals damage lining of arteries
- Increased risk of coronary heart disease
- Increase in blood pressure
- Increases risk of cardiovascular disease
- Increased risk of heart attacks and strokes
148
What is excess food stored as?
fat
149
Why is fat good for the body?
It is needed to cushion organs and act as an energy store
150
Why is too much fat bad for the body?
Can cause obesity leading to serious health problems
151
Explain why exercise keeps you healthy.
- More muscle tissue means increased metabolic rate, so less likely to be overweight
- It reduces the risk of arthritis, diabetes and high blood pressure
- Heart will be fitter and develop a better blood supply.
- Lowers blood cholesterol levels and helps balance other cholesterols
- Reduces risk of fatty deposits building up
- Lower risk of heart disease and health problems
152
What type of diabetes is related to obesity?
Type 2
153
What is type 2 diabetes?
When the body either doesn’t make enough insulin to control blood sugar levels or cells stop responding to insulin.
154
Complete the sentence : Type 2 diabetes gets more common with ________.
Age
155
True or false : Some people have a genetic tendency to develop Type 2 diabetes.
True
156
What are the risk factors for type 2 diabetes?
Lack of exercise
Overweight
Obese
Poor diet
157
How can Type 2 Diabetes be treated?
Balanced diet, controlled amounts of carbohydrates, losing weight, regular exercise
OR
Insulin/tablets
158
What type of alcohol is used in alcoholic drinks?
Ethanol
159
Describe what happens after alcohol enters the body.
Ethanol is absorbed into the blood from the gut and passes easily to body tissues, including the brain. It affects the nervous system, making thought processes, reflexes and many reactions slower.
160
What can small amounts of alcohol do to a person?
Makes them feel relaxed, cheerful and reduces inhibitions.
161
What can large amounts of alcohol do to a person?
Lead to a lack of self control and lack of judgment. If the dose is too high, it can lead to unconsciousness, coma and even death.
162
What organs can suffer long-term damage from alcohol?
Liver and brain
163
What can long-term drinking do to the body?
- can develop cirrhosis of the liver
- alcohol is a carcinogen so can cause liver cancer
- damage to the brain can cause it to not function properly
- can cause death
164
What can drinking alcohol whilst pregnant do?
- can cause miscarriage, stillbirths, premature births and low birth weights
- can cause facial deformities, problems with teeth, jaw or hearing, kidney, liver, and heart problems
- can cause learning or other development issues
- the developing liver of the baby cannot cope causing serious problems to the brain and body
165
What is fetal alcohol syndrome (FAS)?
Issues caused by drinking alcohol during pregnancy.
166
Give 4 examples of ionising radiation.
- Ultraviolet (from sun)
- Radioactive materials (found in soil, water and air)
- Medical and dental X-rays
- Accidents in nuclear power generation
167
How do plants make their food?
By photosynthesis
168
Where does photosynthesis take place?
Chloroplasts
169
What do chloroplasts contain for photosynthesis?
Chlorophyll
170
What is the word equation for photosynthesis?
Carbon dioxide + water
—>
Oxygen + Glucose
171
What is the balanced equation for photosynthesis?
6CO2 + 6H2O
—>
C6H12O6 + 6O2
172
What type of reaction is photosynthesis?
endothermic
173
What is the by-product of photosynthesis?
Oxygen
174
What is glucose from photosynthesis used for in plants?
- Cells for respiration
- Converted into cellulose for strength
- Converted into starch for storage
- Used to make amino acids
- Used to make lipids
175
How can you show that a plant produces oxygen? RP
Place a water plant in a beaker of water.
Collect bubbles of gas in a tube, given off when the plant is photosynthesising. It will relight a glowing splint proving it is oxygen.
176
Give 6 adaptations of leaves for photosynthesis.
1- large surface area to absorb light
2- thin so diffusion of gases is short
3- contain chlorophyll to absorb light
4- contain veins that provide plenty of water
5- have air spaces to allow co2 in and o2 out
6- have guard cells to open and close stomata for gas exchange
177
What are limiting factors?
Things that are in short supply so limit the amount of a function.
178
What are the 4 limiting factors of photosynthesis?
Light, Carbon dioxide concentration, Temperature and Chlorophyll
179
How can light limit the rate of photosynthesis?
If there is plenty of light, then lots of photosynthesis can take place.
If there is little or no light then photosynthesis will stop.
180
How can temperature affect the rate of photosynthesis?
The higher the temperature, the faster the rate of reaction. However if the temperature exceeds a certain amount enzymes can denature meaning photosynthesis can no longer take place.
181
What percentage of the atmosphere is carbon dioxide?
0.04%
182
How can carbon dioxide concentration affect the rate of photosynthesis?
The higher the concentration carbon dioxide, the faster the rate of photosynthesis.
183
How can you investigate light intensity on the rate of photosynthesis?
https://www.bbc.co.uk/bitesize/guides/zs4mk2p/revision/5
184
How can the amount of chlorophyll affect photosynthesis?
If the amount of chlorophyll is limited, less light energy is absorbed so less photosynthesis takes place
185
What factors can affect the amount of chlorophyll produced?
Amount of minerals, especially magnesium.
186
What does light intensity involve?
The inverse square law
187
What is the inverse square law?
As the distance of light from the plant increases, the light intensity decreases.
Light ∝ 1/distance^2
188
True or false: Glucose is soluble in water.
True
189
True or false : Starch is soluble in water.
False - Starch is insoluble
190
How does a greenhouse affect the rate of photosynthesis?
The atmosphere is warmer, speeding up the rate of photosynthesis
191
What is aerobic respiration?
When glucose reacts with oxygen, energy is transferred to cells so they can complete their functions.
192
What are waste products of aerobic respiration?
Carbon dioxide and water
193
What type of reaction is aerobic respiration?
Exothermic
194
Complete the sentence : All living things _______.
Respire
195
What is the word equation for aerobic respiration?
Glucose + Oxygen
—>
Carbon dioxide + water
196
What is the balanced equation for aerobic respiration?
C6H12O6 + 6O2
—>
6H2O + 6CO2
197
Where does aerobic respiration take place?
Mitochondria
198
How are mitochondria adapted for respiration?
They have a folded inner membrane that provides a large surface area for the enzymes involved in respiration.
199
Why is respiration needed in living cells?
They need energy to carry out basic functions. Energy is required for synthesis reactions (building reactions).
200
Why is respiration needed in animals?
Energy is transferred to make muscles contract.
201
Why is respiration needed in mammals and birds?
To maintain a constant internal body temperature. On cold days, energy is required to increase the temperature and on warm days energy is required to decrease the temperature.
202
Why is respiration needed in plants?
Energy is needed to
- move minerals from the soil into root hair cells
- convert sugars, nitrates and other nutrients into amino acids
203
What is muscle tissue made up of?
protein fibres
204
What do muscle cells contain a lot of? Why?
Mitochondria as large amounts of energy from respiration are required for muscle contraction.
205
What do muscles store glucose as?
glycogen
206
What happens to the muscles during exercise?
They produce large amounts of carbon dioxide
207
What 3 things happen to the body when muscular activity increases during exercise?
1- Heart rate increases, arteries dilate increasing the flow of oxygenated blood, increasing supply of oxygen and decreases carbon dioxide
2- Breathing rate and depth increases, oxygen enters the body faster and carbon dioxide exits the body faster
3- glycogen stored in the muscles is converted into glucose to supply cells for respiration
208
True or false: The resting heart beat and breathing rate of an unfit person is faster than that of a fit person.
True
209
What type of respiration takes place when the oxygen supply to muscles isn’t fast enough?
Anaerobic respiration
210
What is the word equation for anaerobic respiration?
Glucose —> Lactic acid
211
What does the build up of lactic acid in the muscles create?
An oxygen debt
212
What is oxygen debt?
The amount of oxygen needed to convert the lactic acid back into glucose.
213
Where is lactic acid converted back into glucose?
The liver
214
What is the word equation for oxygen debt repayment?
lactic acid + oxygen
—>
carbon dioxide + water
215
When plants respire anaerobically, what is formed?
ethanol and carbon dioxide
216
What is anaerobic respiration in yeast known as?
fermentation
217
What is the metabolism of an organism?
The sum of all the reactions that take place in a cell or in a body.
218
Give 6 examples of metabolic reactions.
1- glucose to starch, glycogen and cellulose
2- lipid molecules from a glycerol molecule and 3 fatty acid molecules
3- the use of glucose and nitrate ions to amino acids and then proteins
4- reactions of respiration
5- reactions of photosynthesis
6- break down of proteins in liver to form urea
219
What is the liver?
A large, reddish-brown organ that carries out many functions
220
Give 3 metabolic reactions that take place in the liver.
1- detoxify poisonous substances e.g. ethanol
2- passing breakdown products into blood so they can be excreted in the urine via kidneys
3- breaking down old, worn out blood cells and storing iron until it needs to make more blood cells
221
Explain how the liver removes lactic acid.
1- Blood flowing through muscles transports lactic acid to liver
2- In liver, lactic acid is converted into glucose and oxygen debt is repaid
3- If glucose is not needed it is converted into glycogen and stored in the liver
222
Approximately how much does the liver weigh?
1.5kg
