biology

what is a glandular tissue

it is a tissue that produces digestive juices that break down food

what is an epithelial tissue

a tissue that covers the inside and outside of the stomach

list the organs in the digestive system

liver

kidneys

small intestine

large intestine

stomach

pancreas

organ system meaning

when different groups of organs work together to do a specific job

what is the purpose of enzymes

to break food down into smaller molecules that can be absorbed by blood

what is a balanced diet

a diet consisting of a variety of food, which provides adequate amounts of the nutrients needed for good health

what is a nutrient

a nutrient is a substance that provides nourishment

why is fibre not classed as a nutrient

as it helps food move through the gut but does not nourish

what enzymes break down protein into amino acids

protease

what enzymes break down starch into glucose

amylase

what enzymes break down lipids into fatty acids

lipase

what does the iodine test identify

starch in foods

what does the benedicts test identify

reducing sugars such as glucose or fructose

what does the ethanol test identify

lipids

what does the biuret test identify

protein

describe how amylase is broken down using the lock and key model

amylase is an enzyme that breaks down starch into glucose

using the lock and key theory the substrate will fit perfectly in the enzyme amylase because they have a complementary shape

the enzyme and substrate attach at the active site, which breaks the substrate into products

what is the role of bile in the liver

to neutralize acid and emulsify fat

what is diffusion

it is the movement of particles from high concentration to low concentration

arteries

go away from the heart

veins

go back to the heart

what is homeostasis

regulation of the body

what do phagocytes do

phagocytes are a type of white blood cell that engulfs and destroys pathogens (phagocytosis)

list the 4 components of blood

plasma

white blood cells

red blood cells

platelets

explain the movement of blood through the heart

deoxygenated blood enters the right atrium through the vena carva

blood flows into the right ventricle through the tricuspid valve

from the right ventricle to the pulmonary artery then to the lungs

oxygonated blood from the lungs goes into the pulmonary vein

blood moves from the pulmonary vein to the left atrium and to the left ventricle

role of the trachea

to carry oxygen to lungs

what happens when the pressure in the chest is higher than outside

the air is forced out of the lungs

how are alveoli maximised for gas exchange

they have a large surface area to maximize the rate of diffusion

they have a rich supply of blood capillaries to maintain steep concentration gradient of carbon dioxide and oxygen in both directions making gas exchange rapid and effective

capillary walls are only 1 cell thick to allow for diffusion to take place over the shortest possible distance between lungs and blood

translocation

the movement of sucrose and assimilates in both directions through the phloem

what is the role of the companion cells surrounding the phloem

they actively pump sucrose in and out of the sieve tubes

what is osmosis

diffusion thats exclusive to the movement of water

what does flaccid mean

a wilting plant

what does turgid mean

a healthy plant

list factors that affect transpiration

temperature

humidity

air movement

light intensity

what is the layer of cells lining the upper surface and lower surface of the leaf

epidermis

what part of the leaf where the most photosynthesis occurs

palisade mesophyll

list symptoms of salmonella

vomiting

#fever

diarrhoea

cramps

list symptoms of gonorrhea

thick yellow discharge from the vagina or penis and pain during urination

what is measles

a very infectious viral disease that is often caught by children

what is athletes foot

a rash caused by a fungus and is usually found between peoples toes and can usually be treated by antifungal medication

what is malaria caused by

protists

list symptoms of malaria

nausea

dry cough

headache

fever

vomiting

how is malaria spread

a mosquito carrying malaria inject plasmodium into the blood stream of the next person they feed on.

the plasmodium passes into the liver and multiplies before passing invading red blood cells

how to prevent malaria

insectiside

antimalarial pills

removal of standing water

what is a communicable disease

an illness that can be passed from person to another

what is a carcinogen

agents that cause cancer or significantly increase the risk of developing cancer

what is a correlation

an apparent link between 2 factors

what is a causal mechanism

something that explains how one factor influences another

list risk factors

age-genetic

second hand smoke-environmental

ionising radiation-environmental

diet-lifestyle

family history-genetic

obesity-lifestyle

gender-genetic

uv rays-environmental

smoking-lifestyle

ethnicity-genetic

blood pressure-lifestyle

alchohol consumption-lifestyle

lack of exercise-lifestyle

what is a tumour

a mass of abnormally growing cells that form when the cells do not respond to normal mechanisms that control growth

what does benign mean

contained in one area, usually within a membrane. does not invade other tissues

what does malignant mean

invading neighbouring tissues and spreading to different parts of the body in the blood, where they form a secondary tumour

what is cancer

a disease caused by an uncontrolled division of abnormal cells in the body which causes a tumour that can spread

what is radiotherapy

cancer cells are destroyed by targetted doses of radiation. it stops mitosis in cancer cells but also damages healthy cells as a consequence

what is chemotherapy

uses chemicals to stop cancer cells from dividing. it is being developed to be cancer specific