Organisation Flashcards
What is a cell?
The basic building block of a living organism
They make up all living things
What is a tissue?
A group of cells with a similar structure and function which all work together to do a function
E.g muscular tissue contracts to produce movement
Glandular tissue produces substances such as enzymes and hormones
Epithelial tissue covers organs
What is an organ?
A group of different tissues working together to preform a specific function
E.g muscle tissue that contracts to churn the contents
Glandular tissues to produce digestive juices
Epithelial tissue to cover the outside and inside of the stomach
What is an organ system?
A group of organs working together to preform specific functions
Lots of organ systems work together to make an organism
E.g the digestive system contains several organs which work together to digest and absorb food
What is the main function of the digestive system?
To digest food and absorb the nutrients obtained from digestion
What is the function of salivary glands?
Produces salvia which contains enzyme carbohydrase
What is the function of the oesophagus?
Tube that connects mouth to stomach
What is the function of the liver?
Produces bile which emulsifies fats to increase surface area which allows lipase enzyme to work more efficiently
Bile also neutralises acid making sure no enzymes are denatured
What is the functions of the gall bladder?
Stores bile
What is the function of the small intestine?
Where soluble food molecules are absorbed into the bloodstream
What is the function of the mouth?
Chews up food
What is the function of the stomach?
Contains protease enzyme and produces hydrochloric acid which kills bacteria and provides the optimum acidic pH for protease enzyme to function
What is the function of the pancreas ?
Produces amylase, carbohydrase,lipase and protease enzymes and releases them into the small intestine
What is the function of the large intestine?
Absorbs water from undigested food, producing faeces
What is the function of the rectum?
Stores faeces
What is the function of the anus?
Where faeces leaves the body
What are enzymes?
Biological catalysts that are made of protein that speed up reactions
What is the role of enzymes in the digestive system?
Enzymes act as biological catalysts which speed up the rate of biological reactions(the breakdown of food) without being used up
How does the shape of an enzyme affect its function?
Enzymes have a specific active site which is complementary to their substrate
What is metabolism?
The sum of all the reactions in a cell or an organism
What types of metabolic reactions do enzymes catalyse?
Building larger molecules from small molecules e.g glucose to starch
Changing one molecule to another e.g glucose to fructose
Breaking down larger molecules into smaller molecules e.g carbohydrates to glucose
What is digestion?
Is the break down of large food molecules into smaller water soluble molecules
What is the muscular system?
Needed for movement
What is circulatory system?
Circulates blood around body
What is reproductive system?
Produces and transports sex cells
What is skeletal system?
Supports the body
What is the alimentary canal?
A muscular tube that runs through the body from mouth to anus
What is the lock and key hypothesis of enzyme function/ how do enzymes work?
Substrate binds to the complementary active site
Forms enzyme substrate complex
Bonds within the substrate are broken
Products are released
What factors affect enzyme action?
PH and temperature
How does temperature affect enzyme action?
Increases temperature increases enzyme action as particles have more kinetic energy so are more likely to collide.
Optimum temp is where enzymes work best-36.5 degrees in humans
When temperature it too hot the enzyme denatures meaning the active site changes shape so it can no longer catalyse the reaction
How does pH affect enzyme function?
Every enzyme has a slightly different optimum pH normally 7
If pH is too extreme the forces that hold the amino acid chains that make up the protein will be affected those will change the shape of the active site and the enzyme may no longer work as it’s been denatured
Describe enzyme amylase
Produced in the salivary gland, pancreas and small intestine
Substrate- starch
Products- glucose
Uses- glucose used in respiration
Describe protease enzyme
Produced in stomach, pancreas and small intestine
Substrate- protein
Products- amino acids
Uses- amino acids used for growth and repair
Describe lipase enzyme
Produced in pancreas and small intestine
Substrate-fats/lipids
Products- fatty acids and glycerol
Uses- fatty acids and glycerol are used to make new fats
How are the products of digestion used?
They are used to build bigger molecules such as carbohydrates and proteins
Glucose is used as a substrate in respiration
What is the role of bile in the digestive system?
Bile is an alkaline substance which neutralises the hydrochloric acid secreted by the stomach
Bile emulsifies lipids to form droplets- this increases the surface area for the lipase enzyme to work
Describe how food is digested in the digestive system
In the mouth physical digestion occurs by chewing
Salivary glands release saliva which contains amylase- this is the start of chemical digestion
Oesophagus transfers food to stomach
In the stomach hydrochloric acid makes food very acidic
In the small intestine food is still acidic which will denature lipase and amylase so need to increase pH using bile
Bile is produced in the liver and stored in the gall bladder
Describe the effect of ph on amylase practical
-Place one drop of iodine solution into each well of a spotting tile
-add 2cmcubed of starch solution into a test tube
-add 2cmcubed of amylase solution into a test tube
- add 2cm cubed of a pH 5 buffer solution into the third test tube - used to control pH
-place all 3 test tubes in a water bath at 30 degrees. Leave for 10 mins to allow the solutions to reach the correct temperature
-combine the 3 solutions into one test tube and mix with a stirring rod. Immediately return test tube to water bath and start a stop watch
- after 30 seconds use a pipette to transfer one drop of solution to a well in the spotting tile which contains iodine
- the iodine should turn blue/ black to show starch is present
- take a sample every 30 seconds and continue until the iodine remains orange
- when iodine remains orange it tells us that starch is no longer present(the reaction has complete)
-repeat the experiment using different pH buffers e.g pH 6,7,8
What are the problems with the practical?
-are only taking samples every 30 seconds so only have an approximate time for the reaction to compete
Could fix this by taking samples every 10 seconds
- noticing when the iodine turns blue/ black isn’t always obvious as the colour change tends to be gradual so can be difficult to see when the reaction has finished.
Can ask different people to look at spotting tile and decide when reaction has completed
What are the variables for effect of pH on analyse practical?
Independent- pH of buffer solution
Dependent- time taken for the starch to be broken down by amylase
Control- volume of solution,temperature
What is the heart?
An organ that pumps blood around the body in a double circulatory system
What is the purpose of the circulatory system?
Carries oxygen and other useful substances to bodily tissues and removes waste substances
How does the double circulatory system work?
Blood passes the heart twice in one cycle through 2 different circuits/pathways
One circuit carries blood from heart to lungs- where the gaseous exchange of oxygen and carbon dioxide takes place
One circuit carries blood from heart to the tissues in rest of the body
Both sides of the heart operate separately
Describe the movement of blood through the heart/ what happens when our heart beats? Cardiac cycle
-deoxygenated blood enters the right atrium through vena cava
-blood moves through a valve and the atrium contracts, forcing blood into right ventricle and valves to shut
- blood then travels to lungs through pulmonary artery
-at the same time
-blood is oxygenated at lungs
-oxygenated blood enters left atrium through pulmonary vein
-blood moves into left ventricle through a valve
-blood then travels to the body through aorta
Why is the double circulatory system important?
It makes the circulatory system more efficient
For example- oxygenated blood can be pumped seeping body at a higher pressure by the left ventricle
Why is the wall of the left ventricle thicker?
Has to pump blood at a higher pressure around the whole body
What are the 4 main blood vessels associated with the heart?
Aorta(left) - carries oxygenated blood from heart to body
Pulmonary vein(left) - carries deoxygenated blood from lungs to heart
Vena cava(right) -carries deoxygenated blood from the body to heat through right atrium
Pulmonary artery (right) - carries deoxygenated blood from heart to lungs
What is the function of valves?
Prevents backflow of blood
What is the purpose of coronary arteries?
Supply the heart muscle with the oxygen it requires ( oxygenated blood)