Biology As Keywords

Front 1

health risks associated with obesity

Back 1

Gall stones
type 2 diabetes
Cancer
Cardio vascular disease

Front 2

what percentage of people are obese?

Back 2

25%

Front 3

Nutrition

Back 3

The total substances taken into an animal or plant to use for metabolic purposes- The total sum of its diet

Front 4

Balanced diet

Back 4

a balanced diet must provide the building blocks for growth, repair and supply sufficient energy.

Front 5

what are the 7 components of a balanced diet and their function?

Back 5

Carbohydrates- energy
Protein- growth, repair
Fat- Insulation
Fibre- digestion
Vitamins- chemical processes inside cells
Minerals- inorganic elements essential to the body's functioning
Water- Transport

Front 6

CHD- Coronary Heart disease

Back 6

A disease affecting the coronary arteries which supply blood to the cardiac muscles of the heart.
-saturated fats increase the risk of CHD i.e people in Scotland eat a lot of meat.
- This can lead to fats and plaque being deposited in the walls of the artery- ATHEROSCLEROSIS which could eventually lead to a heart attack

Front 7

Components thought to reduce the risk of CHD

Back 7

Fibre
Oily Fish
Moderate Alcohol consumption

Front 8

Salt in your diet?

Back 8

Salt will decrease the water potential of your blood. This causes water to remain in the blood and the blood pressure increases. This can lead to hypertension which can damage the arteries leading to atherosclerosis

Front 9

Cholesterol

Back 9

-made from 4 carbon based rings, found in all biological membranes.
-bile
-sex hormones
-skin
-cell membranes> maintain fluidity
Associated with saturated fats and made in the liver from them.
Cholesterol must be converted into lipoproteins

Front 10

High Density Lipoproteins - GOOD

Maintain a high proportion

Back 10

Unsaturated
body tissues back to liver
receptor on liver cells
decreases cholesterol levels
protects against atherosclerosis

polyunsaturated fats increase the activity of the LDL receptors and decrease the concentration of LDLS in the blood . Monounsaturated fats also seem to help remove them

Front 11

Low Density Lipoproteins- BAD

Maintain a low proportion

Back 11

Saturated
Liver to body tissues
receptor sites on tissues
increases cholesterol levels
promotes atherosclerosis
-saturated fats are thought to decrease the activity of LDL receptors therefore the concentration of LDL's rises in the blood as less is being removed. They are then deposited in the artery walls

Front 12

Name the conditions food spoilage microorganisms need to grow:

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Organic material
Oxygen
Water
Suitable Temperature
Suitable pH

Front 13

Food preservations techniques remove one or several of the conditions needed for orgnaisms to grow.

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Pickling- pH denatures enzymes
cooking- heat denatures proteins
pasteurising- rapid heating kills microorganisms
Drying/salting- Dehydrates microorganisms
smoking- food develops a hardened surface and smoke contains anti-bacterial chemicals
irradiation- disrupts DNA
cooling/freezing: slows enzyme activity
canning- deprived of oxygen
Vacuum- no oxygen
plastic/ paper wrapping- microorganisms can't get on to the food

Front 14

Fertilisers

Back 14

Replace minerals in the soil
increase growth rate and overall size of crop

Front 15

Pesticides

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Designed to kill microorganisms that cause disease and reduce the yield of the crop

Fungicides are used to reduce fungal growth on roots and leaves

Front 16

Antibiotics

Back 16

infected animals can be treated with these (especially in intensive farming units) to reduce the spread of disease

Front 17

Single Cell protein

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Mycoprotein or single cell protein. Marketed as Quorn. Grown using microorganisms in large vats and is used as a substitue to meat.
It contains no saturated fats or cholesterol

Front 18

Parasite

Back 18

lives on or in another living thing causing harm to its host
external- fleas, ticks
internal- tapeworm

Front 19

Pathogen

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An organism which causes disease. Take nutrition from their host but also cause damage in the process.

Front 20

Health

Back 20

if you are in good health you are:
- free from disease
-able to carry out all normal physical and mental tasks expected in modern society
-well fed, with a balanced diet
- usuall happy, positive outlook
- suitably housed with proper sanitation
- well intergrated in society

Front 21

Disease

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is a departure of good health caused by a malfunction of the body or mind which causes symptoms

Front 22

Primary defences

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Skin- keratinsation, by the time the cells reach the surface , they are no longer alive. Eventually the dead cells slough off. The keratinised layer of dead cells acts as an effective barrier to pathogens

Mucous membranes- Areas such as the airways lungs and digestive system are protected my mucous membranes. The epithelil layer contains goblet cell which secrete mucus. The mucus traps any pathogens in the airways and the cilia waft it up the trachea. It enters the oesophagus where it is swallowed and passed into the digestive system. The pathogens are killed by the pH in the stomach

others: eyes are protected by tear fluid, ear canal is lined by wax, acidic conditions in vagina

Front 23

Phagocytes- Secondary defence

Back 23

Many trapped pathogens are not killed by the conditions in the body. They must be killed before the reproduce and cause symptoms of disease

Neutrophils- multilobed, manufactured in bone marrow. They travel in the blood and in tissue fluid. Can be found on epithelial surfaces such as the lungs, short lived and are released in large numbers as a result of infection

macrophages- larger cells, made in bone marrow, travel in the blood as monocytes, settle in LYMPH NODES and develop into macrophages.

Front 24

phagocytosis

Back 24

Phagocytes engulf and destroy pathogenic cells.

1) when a pathogen enters the body it is recognised as foreign by the chemical markers on its outer membrane- ANTIGENS.

2)proteins in the blood -ANTIBODIES attach to the foreign antigens.
3)phagocytes have membrane bound proteins which act as receptors. The receptor binds to the pathogen already attached to the pathogen.
4) once the phagocyte is bound to the pathogen, it will envelop the pathogen by folding its membrane inwards.
5) the pathogen is trapped inside a vacuole called a phagosome.
6)Lysosomes fuse with the phagosome and release enzymes into it. The lysins digest the bacteria and the end products are harmless nutrients which are then absorbed into the cytoplasm.

Front 25

immune response

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is the specific response to a pathogen, which involves the action of lymphocytes and the production of antibodies

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Antigens

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A foreign molecule that provokes an immune response. Organisms have antigens on their plasma membranes.

Front 27

Antigen presenting cells

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A macrophage that has ingested a pathogen and displays the pathogen's antigens on its cell surface membrane

Front 28

Antibodies

Back 28

protein molecules that can identify and neutralise antigens

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The structure of antibodies

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4 polypeptide chains held together by disulphide bridges
A constant region which enables the antibody to attach to phagocytic cells and helps in the process of phagocytosis.
variable region- has a specific shape and differs from one type of antibody to another as a result of its amino acid sequence. It ensures that the antibody can attach only to the correct antigen. It is complementary
Hinge regions- allow flexibility. Allow branches of the Y shaped molecule to move further apart to allow attachment to more than one antigen

Front 30

How antibodies work

Back 30

Most antibodies work by attaching to the antigens on a pathogen. The pathogen may have another use for this molecule. For example, it may be a binding site, which would be used to bind to the host cell. If the antibody blocks this binding site the pathogen cannot bind to the host cell. NEUTRALISATION has occured.

Aggulutination- a large antibody can bind many pathogens together at once. The group of pathogens is too large to enter a host cell

Front 31

Producing antibodies

Back 31

it takes a few days before the number of antibodies in the blood rises to a level that can combat infection succesfully. - PRIMARY immune defence

Antibodies do not stay in the blood. If the body is affected by the same pathogen for a second time the antibodies must be made again. However, the immune system can swing into action more quickly. As a result, the concentration of antibodies rises sooner and is more rapid. SECONDARY IMMUNE RESPONSE