organisation Flashcards
1
Q
what is a cell
A
basic building blocks of all living organism
2
Q
what is a tissue
A
group of similar cells that work together to carry out a particular function
3
Q
give examples of 3 different types of tissue and what they do
A
muscular tissue - contract to bring about movement
glandular tissue - produces and secretes substances like enzymes
epithelial tissue - covers the outside of your body and internal organs
4
Q
what is an organ
A
aggregation of tissues performing specific functions
5
Q
what do the different tissues that make up the stomach do
A
muscular tissue churns the food and digestive juices together
glandular tissue produces the digestive juices which break down food
epithelial tissue covers the inside and outside of the stomach
6
Q
what is an organ system
A
when different organs work together to perform a particular function
7
Q
what are the different organ systems in the human body
A
circulatory system respiratory system nervous system reproductive system digestive system excretory system endocrine system
8
Q
what does the digestive system do
A
carries out the process of digestion of food
9
Q
what are the two functions of the pancreas
A
makes hormones to control blood sugar as well as enzymes which are made by two different tissues
10
Q
what are the different organs that make up the digestive system
A
mouth gullet diaphragm stomach liver pancreas gall bladder bile duct large intestine small intestine rectum anus
11
Q
what happens in the mouth during digestion
A
using our teeth we physically break down food by chewing
saliva is released from our salivary glands which helps makes the mixture more liquid
salivary amylase breaks down carbohydrates
12
Q
what happens in the gullet during digestion
A
chewed up food gets passed down the gullet (oesophagus) and into our stomach
13
Q
what happens in the stomach during digestion
A
- contracts muscular walls to push food around
- produces pepsin which is a protease that breaks down protein
- produces hydrochloric acid which kills bacteria and creates the right environment for pepsin
14
Q
what happens in the small intestine during digestion
A
soluble food molecules are absorbed into your blood and transported around your body
it also produces enzymes to aid digestion
15
Q
what does the pancreas do in digestion
A
the pancreas produces most of them enzymes used to aid digestion and pushes them into the small intestine in the form of pancreatic juices
16
Q
what happens in the gull bladder during digestion
A
the gall bladder releases bile into the small intestine
17
Q
what does bile do
A
neutralises the acid from the stomach as the bile itself is alkaline
emulsified fat into balls of tiny droplets which gives it a much bigger surface area for enzymes to work on
18
Q
where is bile made
A
in the liver but is stored in the gull bladder until it needs to be released into the small intestine
19
Q
how is the small intestine adapted to its function
A
- covered in villi which gives it a large surface area
- villi is only one cell thick which creates a short diffusion distance
- good blood supply to maintain the concentration gradient
20
Q
what is left over in the small intestine
A
watery, indigestible food
21
Q
what happens in the large intestine during digestion
A
left over material in the small intestine is passed over into the large intestine
the large intestine absorbs all of the excess water leaving behind faeces
22
Q
what happens in the rectum during digestion
A
faeces produced by the large intestine is stored in the rectum until removed
23
Q
what is a catalyst
A
a substance that increases the speed of a reaction without being changed or used up in the process
24
Q
what is an enzyme
A
a particular type of catalyst made by living organisms
25
what are enzymes made of
they are proteins made up of long chains of amino acids which are folded into unique shapes
26
how do enzymes work
enzymes speed up the rate of chemical reactions
they are able to do this because they have an active site which is a region on the enzyme that has a specific shape that is specific to the substrate of the reaction
27
why is the shape of the active size important
if the substrate doesn’t fit the unique shape of the active site it cannot be catalysed
28
what are the 2 different models of enzyme action
1. lock and key - that the substrate has to fit perfectly into the enzyme like a lock and key
2. induced fit - the substrate doesn’t have to fit perfectly into the enzyme and the enzyme even changes its shape slightly to fit around the substrate
29
what happens when an enzyme is denatured
temperature increase the rate of a reaction. however, once the temperature reaches 40 and above the long amino acid chains unravel and the shape of the active site is changed. this means that the specific substrate won’t be able to fit into the active site.
30
at what temperature do enzymes work best (optimum temperature)
37 degrees celsius which is the human body temperature
31
why is it dangerous for our temperature to get too high
if we’re ill and our temperature gets too high, our enzymes will start to become denatured and won’t work fast enough to keep us alive
32
do ALL enzymes work best at 37?
no, different enzymes can have different optimum temperatures but 37 is the most common
33
how does the pH affect the enzyme
if the pH is too high or too low it can change the shape of the active site. at first the site is slightly changed which just slows down the reaction but it will eventually change too much and become denatured
34
what is the optimum pH for enzymes
the optimum pH depends on where the enzyme is
most enzymes have an optimum pH of 7
enzymes in the stomach have a more acidic pH of around 2
35
how do you calculate the rate of reaction
how much a certain product or reactant changes by / time taken for it to change
36
how are carbohydrates broken down
carbohydrates are broken down by amylase into smaller sugars such as glucose, sucrose and maltose
37
where is amylase made
salivary glands
pancreas
small intestine
38
how are proteins broken down
proteins are broken down by protease into amino acids
39
where is protease made
stomach (pepsin)
pancreas
small intestine
40
how are lipids broken down
lipids are broken down by lipase into 3 molecules of fatty acids and glycerol
41
where is lipase made
pancreas and small intestine
42
how can you test for sugar (reducing)
benedicts solution:
add benedicts solution to food sample
let it heat up
if no sugars are present solution will stay blue
if sugars are present the solution will turn brick red
43
how can you test for starch
iodine test:
add iodine solution to food sample
if starch isn’t present the solution will stay an orange colour
if starch is present the solution will become a dark blue/black colour
44
how can you test for proteins
biuret test:
add biuret solution to food sample
if the solution stays blue protein isn’t present
if the solution turns pink/purple protein is present
45
how can you test for lipids
sudan 3 test:
add 3 drops of the sudan 3 stain solution to 5 cm^3 of your unfiltered food sample and shake, if lipids are present the sample should be stained bright red
46
what functions do proteins carry out in our body
they act as
- structural components of tissues such as muscles and tendons
- hormones such as insulin
- antibodies
- enzymes
47
what happens to the completely digested soluble molecules in your small intestine
they are then passed into your bloodstream to be carried around your body and into cells that need them
48
how is the small intestine adapted to digestion
- lining covered in vili to increase the surface area which means digested food can be absorbed quickly
- single layer of surface cells means there is a short diffusion distance
- good blood supple to maintain the concentration gradient
49
what is gas exchange
oxygen diffusing into blood (for cellular respiration) and carbon dioxide diffusion out
50
what are the different parts of the gas exchange system
```
nose
mouth
trachea
bronchi
bronchioles
alveoli
the heart
intercostal muscles
ribs
diaphragm
```
51
what is the diaphragm
a strong sheet of muscle which moves up and down during gas exchange
52
how are alveoli adapted for gas exchange
- one cell thick which creates a short diffusion distance
- large surface area which allows more diffusion
- moist walls which allows gases to dissolve
- good blood supply from capillaries which maintains the concentration gradient
- steep gradient as the red blood cells have very little oxygen and the alveoli have lots of oxygen
53
how is carbon dioxide exchanged
the carbon dioxide from the blood diffuses into the alveoli down the concentration gradient and then we can just breathe it out
54
what is the role of the circulatory system
to transport oxygen and nutrients to our body
55
what makes up the circulatory system
- blood
- blood vessels
- the heart
56
why is the circulatory system known as a double pump systems
one part of the heart pumps blood to the lungs and then back to the heart
another part of the heart carries oxygenated blood to the rest of the body and then back to the heart
57
what are the names of the chambers of the heart
top two chambers are the atria
| bottom two chamber are the ventricles
58
what is the job of the valves
prevents back flow of the blood and makes sure it Is always flowing in the right direction
59
which two blood vessels allow blood into the heart
deoxygenated blood from vena cava in the right atrium and oxygenated blood from the pulmonary vein in the left atrium
60
what happens after the vena cava and pulmonary vein bring blood into the heart
- atria contract and push the blood into the ventricles
- ventricles then also contract and push the blood back out
- pulmonary artery takes blood to the lungs
- aorta takes blood to the rest of the body
61
what are pacemaker cells
help keep the cycle of the circulatory system steady
| - produce electrical impulses which spread through the muscular walls of the heart to make them contract
62
what is the job of the coronary arteries
provides the heart with its own supple of oxygenated blood and nutrients
63
what are the 3 blood vessels and their functions
- arteries = carry blood away from the heart
- capillaries = exchange nutrients and oxygen with tissues
- veins = carry blood back to the heart
64
what is the structure of the artery
- think layer of muscle and elastic tissue to withstand the high pressure of the blood from the heart
- smaller lumen
65
what is the structure of the capillaries like
- walls are a single cell thick
- permeable wall
- small lumen
66
what is the structure of the vein like
- biggest lumen
- small layer of elastic fibres and smooth muscles as the blood they carry is at a low pressure
- have valves
67
which nutrients are exchanged between the blood in the capillaries and the body tissues
- oxygen
- glucose
- amino acids
68
what does our blood consist of
- red blood cells
- white blood cells
- platelets
- plasma
69
what is the role of red blood cells
to carry oxygen to from the lungs to the cells in our body
70
what is haemoglobin
a red pigment that binds with oxygen
71
how do white blood cells defend our body against pathogens
- phagocytosis = engulfing pathogens
- antibodies which bind onto to pathogens to help destroy them
- antitoxins which neutralise any toxins that pathogen produce
72
what are platelets
small fragments of cells
73
what is the role of platelets
to patch up a wound (clotting) to stop us from bleeding up and stop microorganisms from getting in
74
what is the job of the plasma
makes the blood water so it can flow and carries nutrients, waste products, hormones and antibodies + antitoxins
75
what are the two types of new blood
- artificial blood which is just salt water that adds volume to our circulatory system
- blood transfusion which is real, donated blood
76
what are the two types of new blood
- artificial blood which is just salt water that adds volume to our circulatory system
- blood transfusion which is real, donated blood
77
what are examples of cardiovascular diseases
- coronary heart disease
- heart attacks
- faulty valves
- heart failure
78
what is coronary heart disease
when arteries become clogged up by the build up of fatty material which causes less blood to flow through and therefore less oxygen
79
how is coronary heart diseases treated
stents - tubes inside the artery to open up the arteries
statins - medication which alters the balance of cholesterol, increases good cholesterol and decreases the amount of bad cholesterol
80
how can faulty valves be treated
replacing them with a new valve from either pigs or cows
mechanical valve
however both require surgery and have risks of blood clots
81
what is heart failure.
when the heart can't pump blood around the body properly anymore
82
how can heart failure be treating
- replacing the heart with a new biological one
| - or a artificial heart but they are only temporary
83
what are the problems with replacing the heart
- have to be from a human
- long time to get a donation
- body can reject the new heart
84
what is a communicable disease and how are they caused
infectious diseases which can spread from person to person
caused by viruses, bacteria, parasites and fungi
85
what is a non-communicable disease
cannot be spread between people like asthma, coronary heart disease, diabetes and cancer
86
what is a risk factor
anything that increases the chance that a person will develop a certain disease
87
what are the two different categories of risk factors
- lifestyle eg. obesity
| - environment eg. air pollution
88
what is a tumour
an abnormal mass of cells when group of cells go through uncontrolled growth or division
89
what is a benign tumour
when the group of cells is contained within a certain area usually within a membrane and are therefore not too dangerous
90
what is a malignant tumour
tumours that can spread to different parts of the body to form secondary tumours which is very dangerous and lead to cancer
91
what are the risk factors of different types of cancers
- smoking can lead to lung, mouth and stomach cancer
- obesity can lead to bowel, liver and kidney cancer
- uv light exposure can lead to skin cancer
- drinking alcohol can lead to liver cancer
92
what are stomata
holes which allow gases to diffuse in and out of the leaf
93
what are the different tissues in the leaf
- waxy cuticle
- upper epidermis
- palisade mesophyll (palisade cells)
- spongy mesophyll
- lower epidermis
94
how does the leaf reduce water loss
- waxy cuticle on the top
| - closing their stomata
95
what are guard cells
cells with open and close the stomata of the leaf
96
when do guard cells open and close
open when:
- the plant has a lot of water and the guard cells are turgid
close when:
- the plant doesn't have a lot of water and the guard cells are flaccid
- at night
97
what is translocation
transporting sugars around the plant
98
how are sugars transported in the plant
through the pores of the phloem
99
how does water move through the plant
through the xylem cells
100
what are the 4 factors that affect the rate of transpiration
- temperature
- light intensity
- air flow
- humidity
