B2 Flashcards
(100 cards)
1
Q
Catalyst
A
Substance which increases the speed of a reaction without being used up
2
Q
Catalyst problems
A
Can speed up unwanted reactions
3
Q
Biological catalyst
A
Enzymes
4
Q
Enzymes and active site
A
Large proteins made of chains of amino acids
Each one has a unique active site that fits onto the substrate involved in the reaction
If the substrate doesn’t match the active site then the reaction won’t be catalysed
The active site changes shape to get a tighter fit
5
Q
Substrate
A
Substance an enzyme acts on
6
Q
Why does a reaction need the right temp and ph
A
Temp increases so rate increases
Too hot and enzyme bonds break changing the shape of the active site so the substrate won’t fit (denatured)
If oh too high or low the enzyme will denature
7
Q
What are the optimum temp and ph
A
Temp the enzyme works best at
Normally ph 7
Pepsin breaks down protein in stomach at oh 2 which is acidic conditions
8
Q
Structure of large multicellular organisms
A
Cells, tissues, organs, organ systems
Different systems inside for exchanging and transporting materials
9
Q
Tissues
A
Group of similar cells that work together to carry out a particular function
10
Q
Types of tissues
A
Muscular - contracts to moves what it’s attached to
Glandular - makes and secretes chemicals like enzymes and hormones
Epithelial - covers part of the body - inside the gut
11
Q
A
12
Q
Organ
A
Group of different tissues worked together to perform a certain function
13
Q
Tissues in the stomach
A
Muscular - churns food
Glandular - makes digestive juices to digest
Epithelial - covers stomach
14
Q
Organ system
A
Group of organs working to perform a specific function
15
Q
Organs in the digestive system
A
Glands - produce digestive juices
Stomach and small intestine - digests food
Liver - produces bile
Small intestine - absorbs soluble food molecules
Large intestine - absorbs water from un digested food leaving faeces
16
Q
Why are digestive enzymes needed
A
Starch, proteins and fats are too big to pass through walls of digestive system so digestive enzymes break them down
The smaller molecules can pass easily through the digestive system walls to be absorbed into the bloodstream
17
Q
What do carbohydrases do
A
Convert carbohydrates into simple sugars
18
Q
Example of carbohydrase
A
Amylase
19
Q
What does amylase do
A
Break down starch into maltose
20
Q
Where is amylase made
A
Salivary glands, pancreas, small intestine
21
Q
What does protease do
A
Break proteins into amino acids
22
Q
Where is protease found
A
Stomach, pancreas, small intestine
23
Q
What are the three digestive enzymes
A
Protease, amylase, lipase
24
Q
What does lipase do
A
Break down lipase into glycerol and fatty acids
25
Where is lipase made
Small intestine
Pancreas
26
What is the test for proteins
Get food sample into test tube
Add Biuret solution and shake to mix
Blue colour changes to purple if it’s present
27
Test for sugar
Get food sample into test tube test tube
Prepare water bath to 75 degrees
Add Benedict’s solution to tube
Put test tube in water bath for 5 mins
Blue changes to green, yellow, red if present
Colour depends on how much sugar in food
28
Test for starch
Put food sample in tube
Add iodine and shake to mix
Brown- orange to black/blue if present
29
Test for lipids
Put food sample in tube
Add Sudan 111 stain
Shake to mix
Solution separates lipids into 2 layers and the top will be bright red if present
30
How to get a food sample and why is it needed
To identify the type of food molecule in the sample
Break up piece of food with mortar and pestle
Put food in beaker and add water
Stir mixture to dissolve food
Filter with funnel and filter paper to get rid of solid bits
31
Gall bladder
Where bile is stored and released into small intestine
32
Liver
Where bile is made
33
Pancreas
Produces protease, amylase, lipase
Releases them I got the small intestine
34
Stomach
Churns food with muscular walls
Produce protease
Produce hydrochloride acid to kill bacteria and give right ph for protease to work(Ph2)
35
Large intestine
Where excess water is absorbed from food
36
Small intestine
Produces protease, lipase and amylase to complete digestion
Food is digested and absorbed out of the digestive system and into bloodstream
37
Bile
Produced in liver and stored in gall bladder and released into small intestine
Hydrochloric acid in stomach too acidic to work properly in small intestine so bile is alkaline to neutralise the acid
Enzymes work best in alkaline conditions
It emulsifies fat (breaks) so gives bigger surface area for lipase to work on making digestion faster
38
Investigation for the ph of enzyme activity
1) put drop of iodine into every well on spotting tile
2)put beaker of water on Bunsen burner until 35 degrees
3) add 1cm cubed of amylase solution and buffer solution with ph of 5 to boiling tube and add to beaker for 5 mins
4) add 5 cm cubed of start solution to boiling tube
5) mix contents and start stop clock
6) take sample from tube every 30 seconds and put into a well
7) when the iodine solution remains orange the starch is no longer present
8) repeat with different ph solutions
39
40
How to calculate the rate of reaction
Rate = 100/time
41
What are the parts of the breathing system
Trachea splits to two tubes (bronchi)
Each bronchus goes to a lung
Bronchus split to smaller tubes called the bronchioles
End of bronchioles are small bags called alveoli
42
Where does gas exchange happen
Alveoli
43
Gas exchange
Deoxygenated blood filled with co2 returns to lungs
Oxygen diffuses out of alveoli into blood and co2 diffuses into alveoli to then breathed out
Blood reached body cells and o2 diffuses into them
At same time co2 diffuses out and into red blood cells
44
How is the heart a double circulatory system
Right ventricle pumps deoxygenated blood to lungs to take in oxygen which then returns to heart
In second circuit the left ventricle pumps oxygenated blood around all other parts of the body, blood gives up oxygen at body cells and deoxygenated blood returns to the heart to be pumped out again
45
What is the heart
Organ that keeps blood pumping around the body
46
What does the heart have valves
So blood flows in right direction and prevents back flow
47
What are the four chambers of the heart
Right atrium
Right ventricle
Left atrium
Left ventricle
48
Explain the flow of blood around the body
Deoxygenated blood enters via the vena cava from the body and into the right atrium
It contracts and pushes blood into right ventricle
This contracts and pushes blood through the pulmonary artery to the lungs
The lungs oxygenates the blood via gas exchange and oxygenated blood returns to the heart via the pulmonary vein into the left atrium
Heart contracts and pushes blood into left ventricle
Heart contracts and pushes blood up through the aorta to the rest of the body and into the cells
49
What are coronary arteries
Branch of aorta and surround the heart
They supply oxygenated blood to the heart so it can also function
50
What is your resting heart rate controlled by and how
Group of cells in the right atrium wall acting as pacemaker
They produce small electrical current spreading to surrounding muscles causing them to contract
51
What is an artificial pacemaker and what does it do
Controls heartbeat is natural heart pacemaker cells don’t work normally giving you and irregular heartbeat
Small device implanted under the skin with a wire to the heart producing electrical current
52
What are the three types of blood vessels
Arteries - carry blood away from heart
Veins - carry blood to the heart
Capillaries - involved in exchange of materials
53
54
Arteries features
High pressure blood so walls need to be strong and elastic
Walls are thick compared to lumen (hole in middle)
Thick layers of muscle to be strong and elastic fibres to allow them to stretch and sping back
55
Capillaries features
Really small branding off arteries
Carry blood very close to cells to diffusion of substances
Permeable walls allowing diffusion
Supply food and oxygen and take away co2
Walls are thin to increase rates of diffusion by decreasing distance to travel between
56
Features of veins
Capillaries join to veins
Low pressure so thinner walls
Bigger lumen to increase blood flow
Have valves so blood flows in right direction
57
How to measure blood flow rate
Volume of blood/ num of minutes
58
Function of red blood cells and features
Carry oxygen
Large disk shape so larger surface area for diffusion
No nucleus so more room for oxygen
Red pigment - haemoglobin
Haemoglobin binds to oxygen in lungs becoming oxynaeglobin
Splits up from oxygen in tissues to release it
59
Function of white blood cells
Defend against infection
Change shape to engulf unwelcome microorganisms - phagocytosis
Produce antibodies
Produce antitoxins to neutralise toxins produced by pathogens
Have a nucleus
60
Platelets function and features
Small fragments of cells
No nucleus
Help blood clot at wound
Stop blood pouring out and microorganisms getting in
Lack of platelets cause excessive bleeding
61
What is plasma and what does it carry
Pale straw coloured liquid in blood
Red and white blood cells
Platelets
Glucose and amino acids
CO2
Urea
Hormone
Proteins
Antibodies and antitoxins
62
What is coronary heart disease
When coronary arteries get blocked up by layers of fatty acids building up
Arteries become narrow and blood flow is restricted so lack of oxygen to heart
Can result in heart attack
63
Two ways to treat coronary heart disease
Statins
Stents
64
What are stents
Tubes inserted into arteries
Keep open so blood can pass through to get the heart
65
Advantages of stents
Lower risk of Herat attack
Effective for long time
Surgery recovery time is quick
66
Disadvantages of stents
Infection risk
Complications with surgery
Risk of blood clot near stent
67
What is cholesterol
Essential lipid in body to function
68
What happens if you have too much cholesterol
Health problems
In blood stream causes fatty deposits inside arteries leading to chd
69
What are statins
Drugs that reduce amount of bad cholesterol in bloodstream
Slows down rate if fatty deposits forming
70
Statins advantages
Reduce risks of Herat attacks and chd
Increase Hdl in blood which removes ldl
May prevent other diseases
71
Disadvantages of statins
Long term drug taken regularly do may forget
Side effects like headaches
Effect isn’t instant as takes time to kick in
72
What is an artificial heart
Mechanical device that pumps blood from someone’s heart that has failed
73
Advantages of artificial Heart
Less likely to be rejected by immune system as made by metals and plastics not living tissues
No need for donor heart
74
Disadvantages of artificial hearts
Risk of infection from surgery
Doesn’t work as well as natural ones as could fail
Blood doesn’t flow as smoothly causing clots and strokes
Patient has to take drugs that thin blood so problems with bleeding if hurt
75
What can heart valves be weakened by
Herat attacks
Infection
Old age
Causing tissue to stiffen so doesn’t open properly
76
How are faulty valves treated
Replace valves with either
Biological valves - humans or mammals
Mechanical valves - man made
77
What is risk of replacing valves
Blood clots
78
What is artificial blood
Blood institute to replace lost volume of blood
Gives patient enough time to produce new blood cells if not patient needs blood transfusion
79
What are the two types of disease
Communicable - can spread form person to person
Non communicable - cannot spread and last for a long time worsening like cancer
80
Risk factors of getting a disease
Lack of exercise
Prescence of substances in environment
Smoking
Obesity
Alcohol
Developed countries have better diet
81
What is cancer
Uncontrolled growth and division of cells forming a tumour
82
What are the two types of tumours
Benign - stays in one place, isn’t cancerous, stops growing when no more room left
Malignant - tumour grows and spreads to tissues and through blood, invades healthy tissues, are cancerous
83
Five factors causing cancer
Smoking
Obesity
Uv exposure
Viral infection
Genetics
84
What are the three main organs of a plant
Leaves, stem, roots,
85
What is epidermal tissue in a plant
Covers whole of plant with wax cuticles to reduce water loss through evaporation
86
Function of upper epidermis
Transparent so light can get to palisade layer
87
Function of palisade layer
Photosynthesis occurs
Lost of chloroplasts and near top of leaf for more sunlight
88
Xylem and phloem function
From network throughout leaf
Deliver water and nutrients but take away glucose formed by photosynthesis
89
Spongy mesophyll tissue
Contains big air spaces so gases can diffuse in and out of cells
90
Lower epidermal tissue function
Full of lots of holes(stomata) which let co2 diffuse out of leaf
91
Order from top to bottom of leaf tissues
Upper epidermis
Palisade mesophyll
Xylem and phloem
Spongy mesophyll
Lower epidermis
92
What is a phloem tube
Columns of living cells
Transports food substances made in leaf to rest of plant to store or use - translocation
93
Xylem tubes
Dead cells
Strengthened with lignin
Carry water and minerals from roots and stem to leaves - transpiration
94
What creates a shortage of water in the leaves
Evaporation
95
What does stomata do
Let water escape from leaf
96
What do guard cells do
Open and close stomata
97
When do guard cells open and close the stomata
Too much water - open
Too little water - close
98
What are their more stomata on undersides of leaves
Shaded and cooler so less water is lost through it
99
What four things affect the transpiration rate and how
Light intensity - brighter light so more transpiration as more photosynthesis so more water needed to leaf
Temp - warmer so more transpiration as water has more energy to diffuse out of the stomata
Air flow - more air flow so more transpiration as more diffusion
Humidity - drier air so more transpiration as higher conc gradient so faster diffusion of water
100
Experiment for transpiration
Measure uptake of water by a plant to measure rate
Water uptake is directly linked to water loss by leaves
Record starting position of air bubble
Start watch and record distance moved by bubble in set time
Keep conditions constant ( temp and air humidity )
