Organisation - Principles Flashcards
what are cells
the building blocks that make up all living organisms
what are tissues
a group of similar cells which work together to perform a certain function, can include more than one type of cell
examples of tissues
- muscular tissues which contract
- glandular tissues which make chemicals like enzymes and hormones
- epithelial tissues which covers some parts of the body like inside the gut
what are organs
a group of different tissues that work together to perform a certain function
what is an organ system
a group of organs working together to perform a particular function
how do tissues in the stomach work
muscular tissue moves the stomach wall to churn up the food
- glandular tissue which makes digestive juices to digest food
- epithelial tissue covers the outside and inside of the stomach
whats an organelle
A specialised unit within a cell which performs a specific function
what is an example of an organ system
the digestive system
what does the stomach do in the digestive system
- produces protease enzyme and pepsin
- produces HCl to kill bacteria and to give it the right pH for protease enzyme to work
- digests food
what does the pancreas do in the digestive system do in the digestive system
produces protease, amylase and lipase enzymes
- releases these into the small intestine
what do the salivary glands do in the digestive system
they produce amylase enzymes in the saliva
what does the liver do in the digestive system
- where bile is produced
what does bile do
is made in the liver and stored in the gall bladder. It is alkaline to
neutralise hydrochloric acid from the stomach. It also emulsifies fat
to form small droplets which increases the surface area.
- The alkaline conditions and large surface area increase the rate of fat breakdown by
lipase
what does the gallbladder do in digestive system
- stores bile before it’s ready to be released into the small intestine
what does the large intestine do in the digestive system
absorbs excess water from the food
what does the small intestine do in the digestive system
- produces protease. lipase and amylase enzymes to complete digestion
- also where digested food is absorbed out of the digestive system and into the blood
what does the rectum do in the digestive system
where the faeces are stored
describe how the small intestine is adapted for efficient absorption
- villi projections provide a large surface area
- many capillaries to maintain concentration gradient
- small intestine is very long, increasing time for absorption
- good blood supply to maintain concentration gradient
- cells have many mitochondria for energy release for active transport
what are organelles
a specialised unit within a cell which performs a specific function
what do carbs do and what foods are they found in
- theyre our main source of energy and found in foods such as potatoes, rice, bread
what do proteins do and what foods are they found in
- they are responsible for the growth and repair of cells
- they are found in foods such as meat, eggs, beans
what do lipids do and what foods are they found in
- they make up parts of cell membranes so are essential for growth
- found in foods such as butter, meat, nuts, seeds
why must large molecules such as starch be broken down before it enters the digestive system
because theyre too large to pass through the gut
what is egestion
the process of passing out food that hasnt been digestd
what are glucose molecules used for in the body
- used for respiration
- reassembled into the storage form of carbohydrate in animals - glycogen
what are proteins made up of
amino acids
what does the digestive system do
break large molecules into smaller ones to be absorbed into the bloodstream
what does the churning action of stomach muscles do
turns the food into a fluid, increasing the surface area for enzymes to digest
how is the small intestine adapted for efficient absorption
- it is long, providing a very large surface area for absorption of the products of digestion
- the interior of the small intestine is covered with millions of villi, which massively increase surface area for absorption
- villi have a good blood supply, so the bloodstream rapidly removes the products of digestion, which increases the concentration gradient
- villi have a thin membrane which shortens the diffusion path
if molecules cant be absorbed by diffusion, what are they absorbed by
active transport
