organisation Flashcards
what is a cell
basic building blocks of all living organism
what is a tissue
group of similar cells that work together to carry out a particular function
give examples of 3 different types of tissue and what they do
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
what is an organ
aggregation of tissues performing specific functions
what do the different tissues that make up the stomach do
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
what is an organ system
when different organs work together to perform a particular function
what are the different organ systems in the human body
circulatory system respiratory system nervous system reproductive system digestive system excretory system endocrine system
what does the digestive system do
carries out the process of digestion of food
what are the two functions of the pancreas
makes hormones to control blood sugar as well as enzymes which are made by two different tissues
what are the different organs that make up the digestive system
mouth gullet diaphragm stomach liver pancreas gall bladder bile duct large intestine small intestine rectum anus
what happens in the mouth during digestion
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
what happens in the gullet during digestion
chewed up food gets passed down the gullet (oesophagus) and into our stomach
what happens in the stomach during digestion
- 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
what happens in the small intestine during digestion
soluble food molecules are absorbed into your blood and transported around your body
it also produces enzymes to aid digestion
what does the pancreas do in digestion
the pancreas produces most of them enzymes used to aid digestion and pushes them into the small intestine in the form of pancreatic juices
what happens in the gull bladder during digestion
the gall bladder releases bile into the small intestine
what does bile do
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
where is bile made
in the liver but is stored in the gull bladder until it needs to be released into the small intestine
how is the small intestine adapted to its function
- 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
what is left over in the small intestine
watery, indigestible food
what happens in the large intestine during digestion
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
what happens in the rectum during digestion
faeces produced by the large intestine is stored in the rectum until removed
what is a catalyst
a substance that increases the speed of a reaction without being changed or used up in the process
what is an enzyme
a particular type of catalyst made by living organisms
what are enzymes made of
they are proteins made up of long chains of amino acids which are folded into unique shapes
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
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
what are the 2 different models of enzyme action
- lock and key - that the substrate has to fit perfectly into the enzyme like a lock and key
- 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
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.
at what temperature do enzymes work best (optimum temperature)
37 degrees celsius which is the human body temperature
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
do ALL enzymes work best at 37?
no, different enzymes can have different optimum temperatures but 37 is the most common
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
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
how do you calculate the rate of reaction
how much a certain product or reactant changes by / time taken for it to change
how are carbohydrates broken down
carbohydrates are broken down by amylase into smaller sugars such as glucose, sucrose and maltose
where is amylase made
salivary glands
pancreas
small intestine
how are proteins broken down
proteins are broken down by protease into amino acids
where is protease made
stomach (pepsin)
pancreas
small intestine
how are lipids broken down
lipids are broken down by lipase into 3 molecules of fatty acids and glycerol
