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