Unit 2 Flashcards
(92 cards)
1
Q
What are enzymes?
A
A biological catalyst that speeds up useful chemical reactions in the body.
2
Q
What are enzymes made up of?
A
Proteins which are made up of amino acids.
3
Q
Besides catalysts, what else are proteins in the body?
A
Structure components of tissues (muscles), hormones and antibodies.
4
Q
How do enzymes work?
A
They use the lock and key hypothesis in which each enzyme have an active site in a certain shape that will only fit one substrate so therefore each enzyme can only catalyse one reaction. They enzyme locks onto the substrate and splits it apart or joins it with something else.
5
Q
What happens if an enzyme gets too hot?
A
The bonds holding the enzyme together break which denatures the enzyme (changes its shape).
6
Q
What is the optimum temperature for enzymes in the body to work at?
A
37°C.
7
Q
How does pH affect enzymes?
A
If it is too high or low, the enzyme is denatured.
8
Q
What pH do most enzymes in the body work as?
A
7.
9
Q
What enzyme works best at a pH of 2?
A
Pepsin in the stomach.
10
Q
What converts starch into maltose?
A
Amylase.
11
Q
What converts proteins into amino acids?
A
Protease.
12
Q
What converts lipids into fatty acid and glycerol?
A
Lipase.
13
Q
Where is amylase produced?
A
Salivary glands
Pancreas
Small Intestines
14
Q
Where is protease produced?
A
Stomach
Pancreas
Small Intestines
15
Q
Where is lipase produced?
A
Pancreas
Small Intestines
16
Q
Why are starch, proteins and fats broken down?
A
They are too big to pass through the walls of the digestive system.
17
Q
What is the function of bile?
A
To neutralise stomach acid and emulsify fat.
18
Q
How does bile emulsify fat?
A
It breaks it up into smaller droplets to increase the surface area.
19
Q
Why does bile neutralise stomach acid?
A
So the enzymes in the small intestines have to correct alkaline conditions to work at.
20
Q
What is the job of the small intestines?
A
To absorb the nutrients from food.
21
Q
What is the job of the large intestines?
A
To absorb excess water from food.
22
Q
What is the job of the rectum?
A
To store faeces.
23
Q
What is respiration?
A
The process of releasing energy from the breakdown of glucose.
24
Q
Where does respiration take place?
A
In every cell in the body.
25
What does aerobic respiration require to happen?
Oxygen.
26
What is the most efficient way to release energy from glucose?
Using aerobic respiration.
27
Where do most of the aerobic respiration reactions take place?
In the mitochondria in cells.
28
What is the word equation for aerobic respiration?
Glucose + Oxygen --------> Carbon Dioxide + Water + Energy
29
How is the energy from respiration used? (4)
To build larger molecules from smaller ones (proteins from amino acids.
To allow muscles to contract.
To maintain body temperature.
In plants, to build sugars, nitrates and other nutrients into amino acids.
30
What are muscles made up of?
Muscle cells.
31
What happens in the body during exercise? (3)
Breathing rate increases.
Heart rate increases.
Breathing Depth.
32
What happens to glycogen in the liver during exercise?
It is converted back into glucose as the muscles in the body use up glucose rapidly.
33
What two things does anaerobic respiration cause?
Muscle fatigue and a build up of lactic acid.
34
What is anaerobic respiration?
Respiration without oxygen.
35
What is the word equation for anaerobic respiration?
Glucose -------> energy + lactic acid.
36
What is the advantage of anaerobic respiration?
You muscles can work for a little bit longer (for the final sprint).
37
What is oxygen debt?
When the body anaerobically respires, your muscles don't get enough oxygen so you must take in more so that the lactic acid can be oxidised to form CO2 and water.
38
How do you remove oxygen debt?
Breathing in more deeply.
39
What are enzymes used for in industry?
Biological detergents and washing powders.
40
What are the main enzymes in detergents and washing powders?
Proteases and lipases.
41
Why are enzymes used for washing powders?
They can break down stains like food and blood.
42
Why are biological detergents better than other detergents?
They work at lower temperatures.
43
How are enzymes used in food? (3)
They are used in pre-digested baby food (protease).
Turning starch syrup into glucose syrup (carbohydrase).
Glucose syrup can be turned into fructose syrup using isomerase - fructose is sweeter so you can use less which is good for slimming products.
44
What are the advantages of using enzymes in industry? (4)
They are specific so can only catalyse the reaction you want.
They use lower temperatures and pressures so are cheaper.
They work for a long time.
They re biodegradable so are produce less environmental pollution.
45
What are the disadvantages of using enzymes in industry? (4)
People are allergic to them.
They can be denatured by even the smallest change of pH and temperature.
They can be expensive to produce.
Enzymes can be contaminated.
46
What are the 5 parts of an animal cell?
Nucleus, Cytoplasm, Cell Membrane, Mitochondria, Ribosomes.
47
What are the 3 extra parts of a plant cell?
Vacuole, Cell Wall, Chloroplasts.
48
What are the 4 parts of a yeast cell?
Cell Membrane, Cell Wall, Cytoplasm, Nucleus.
49
What are the 4 parts of a bacteria cell?
Genetic loop, Cell Wall, Cell Membrane, Cytoplasm.
50
What is diffusion?
The spreading out of particles from an area of high concentration to an area of low concentration.
51
What must the membrane be for diffusion to take place?
Partially Permeable.
52
What molecules cannot diffuse into cells?
Starch and proteins because they are too big.
53
What molecules diffuse into cells?
Glucose, water and amino acids.
54
How are palisade leaf cells adapted for photosynthesis? (3)
They have a lot of chloroplasts to absorb more sunlight.
Tall shape exposed down the side to absorb more CO.
Thin shape to pack a lot into the top of the leaf.
55
How are guard cells adapted to open and close pores? (3)
When the plant has lots of water, they become turgid and open the stomata for gaseous exchange to take place. When the plant has less water, they become flaccid and close to reduce water loss.
They are sensitive to light ot close at night to reduce water loss.
They have thick inner walls and thin outer walls to make the opening and closing work.
56
How are red blood cells adapted to carry oxygen?
Concave to increase surface area.
Lots of haemoglobin.
No nucleus to carry more haemoglobin.
57
How are sperm cells adapted?
Tail and head to make more streamlined.
Lots of mitochondria to produce more energy.
Carry enzymes in there head to digest through the egg cell membrane.
58
How are egg cells adapted?
They carry food reserves for the developing embryos.
| Their membrane changes instantly when the sperm fuses with it so that no more can fuse with it.
59
What is differentiation?
When cells become specialised for a particular job.
60
What are tissues?
A group of similar cells that work together to carry out a particular function.
61
What is the job of muscular tissue?
To contract and relax to move to move whatever it is attached to.
62
What is the job of glandular tissue?
To make and secrete chemicals like enzymes and hormones.
63
What is the job of epithelial tissue?
To cover some parts of the body for example the lining of the gut.
64
What is an organ?
A group of different tissues that work together to perform a certain function.
65
What is the job of muscle tissue in the stomach?
To churn up the food.
66
What is the job of glandular tissue in the stomach?
To secrete digestive juices to digest food.
67
What is the job of epithelial tissue in the stomach?
To cover the inside and outside of the stomach.
68
What is an organ system?
A group of different organs working together to perform a particular job.
69
What is the mesophyll tissue?
The part of a leaf where most of the photosynthesis occurs.
70
What is the xylem?
The plant tissue that transports water around the plant.
71
What is the phloem?
The plant tissue that transport food like glucose around the plant.
72
What is epidermal tissue?
Tissue that covers the plant.
73
What is the equation for photosynthesis?
Carbon Dioxide + Water ---------> Glucose + Oxygen
74
Where does photosynthesis take place?
In the chloroplasts.
75
What do chloroplasts contain?
Chlorophyll which is a green pigment that absorbs sunlight.
76
What is a limiting factor?
Something that stops photosynthesis occurring any faster.
77
What is the limiting factor of photosynthesis at night?
Light.
78
What is the limiting factor of photosynthesis in winter?
Temperature.
79
What is the limiting factor of photosynthesis in summer?
Carbon Dioxide.
80
What experiment can be done to find the best conditions for photosynthesis to occur?
Canadian Pondweed experiment.
81
How can light in greenhouses be artificially created?
Lamps.
82
How can CO2 and temperature in greenhouses be artificially created?
Burning paraffin in a heater as it increases heat and produces CO2 as a bi-product.
83
Besides condition control, what else are greenhouse good for?
Protecting plants against pests and diseases.
84
What 5 things do plants use glucose for?
Respiration, Starch, Proteins, Cellulose, Oil.
85
Why do plants store glucose as starch?
For use when photosynthesis isn't happening for example in winter.
86
What environmental factors affect organism distribution? (5)
Temperature, Availability of Water, Availability of Oxygen and Carbon Dioxide,Availability of Nutrients, Amount of Light.
87
How do you use quadrats?
1. Place 1m² quadrat in random location.
2. Count organisms in the quadrat.
3. Repeat steps 1 and 2.
4. Calculate mean.
88
How do you calculate population size?
Work out the mean number of organisms per 1m² using quadrats.
Multiply mean by total area.
89
What are transects and what do they measure?
They are a line that data is collected along. They measure the distribution of a population.
90
In terms of data, what is meant by 'reliable'?
Making sure the data is reproducible and repeatable.
91
How can reliability be increased? (1)
Make the sample size bigger.
92
How can validity be increased? (3)
Answer the original question.
Use random samples.
Control all variables.
