Organisation Flashcards
Tissue
A group of cells with a similar structure and function
e.g. Muscle cell
Organ
A group of tissues working together for a specific function
e.g. Stomach
Organ system
A group of organs that work together to form organisms
What are the 3 main nutrients from food
Carbohydrates (starch)
Protein
Lipids (fat)
What does the Mouth do
Food is chewed in the mouth.
Enzymes in the saliva begin to die jest the starch into smaller sugar molecules
Where does the food go after chewing it?
The food then passes down the oesophagus into the stomach.
In the stomach enzymes begin the digestions of proteins, the stomach also contains hydrochloric acid which helps the enzymes to digests proteins.
What does the stomach muscles do in digestion
The churning action of the stomach muscles turns the food into a fluid increasing the surface area for the enzymes to digest.
What does the small intestines do in digestion
Fluid passes into the small intestines from the stomach.
The walls of the small intestines release enzymes to continue the digestions of proteins and lipids.
The small food molecules produced by digestion, are absorbed into the bloodstream either by diffusion or active transport.
What does the pancreas do in digestion
Releases enzymes which continue the digestion of starch and protein.
They also start the digestions of lipids.
It also release bile.
What does bile do in digestion
The liver releases bile which helps to speed up the digestion of lipids.
Bile also neutralises the acid released from the stomach.
Digestive system
Large food molecules are digested into smaller molecules, and then the products of digestions are absorbed into the bloodstream.
Glucose produced can be used for energy
What do enzymes speed up
Enzyme catalyse (speed up) chemical reactions
What are enzymes
Large protein molecules and they have a groove on their surface called the active site
What is the active site
Where the substrate attaches to (lock and key)
What does enzymes do
Breaks down the substrate into the products
Protease
Enzymes that break down proteins
What are proteins
Long chains of chemicals called amino acids
Are Amino acids absorbed
Are absorbed into the bloodstream
Starch
Chains of glucose molecules
Carbohydrases
Enzymes that break up carbohydrates.
In the case of starch this is called amylase.
What happens when carbohydrates (like starch) are digested
We produce simple sugars
Where are amylase found
In the saliva and pancreatic
What do lipid molecules consist of
A molecule of glycerol attached to 3 molecules of fatty acid
Lipase
Enzymes that digests lipid molecules.
This produces glycerol and fatty acid
Where are lipase found
In the pancreatic fluid and also in the small intestines
Where is bile made
In the liver and it is stored in the gallbladder
What does bile do
- It helps to speed up the digestion of lipids but bile is not an enzyme
- Bile converts large lipid droplets into smaller droplets
- Bile emulsifies the lipid
- neutralises stomach acid, and creates alkaline conditions in the small intestines
What happens to the activity of the enzyme if we increase the temperature
The activity of the enzyme increases the reaction gets faster
Small intestine are 5m, what does this mean
this provides a very large surface area for the absorption of the products
Villi in the small intestine
The inside of the small in testing is covered with millions of villi.
Villi massively increases the surface area for absorption of molecules.
What are benefits Double circulatory system
because the blood passes through the heart twice the can travel rapidly to the body cells delivering the oxygen that the cells need
Heart
An organ consisting mainly of muscle tissue, the heart pumps blood around the
The heart has 4 chambers, name them all
Left atrium (at the top) Right atrium (at the top) Left ventricle (at the bottom) Right ventricle (at the bottom)
What separates the ventricles
The atria are separated from the ventricles by valves
What does the Vena cava do
It brings deoxygenated blood from the body
it is located on the right side of the heart
What is the pulmonary artery
The blood passes from the heart to the lungs in the pulmonary artery
What is the pulmonary vein
Oxygenated blood passes from the lungs to the heart in the pulmonary vein
It is located on the left side of the heart
What is the aorta
Oxygenated blood is pumped from the heart to the body in the aorta
Where does blood into the heart
Blood enters the left atrium and the right atrium
Where does the blood exit the heart
Ventricles contract and force the blood out of the heart
What does the left side of the heart have got the right side doesn’t
The left side the heart has a thicker muscular wall on the right side - because the left ventricle pumps blood around the entire body so it needs to provide a greater force
Coronary arteries
Branch out of the aorta and spread out into the heart muscle
They provide oxygen to the muscle cells of the heart
What do arteries carry
Very high pressure blood from the heart to the organs in the body
why do arteries have a very thick muscular wall
It allows them to with stand the very high pressure of the blood
Capillaries
When the blood passes through the capillaries, substances such as glucose and oxygen defuses from the blood to the cells
What defuses from the cells back to the blood in capillaries
Carbon dioxide
Why do capillaries have very thin walls
the diffusion path is very short
What does the thin walls in the capillaries affect
It allows substances to diffuse rapidly between the blood and the body cells
The circulatory system
Once the blood has passed through the organs, it now makes its way back too the heart in veins
Why do veins have then walls
The blood pressure is low so the walls don’t have to be thick
What is the job of the valves
Many veins contain valves.
The job of the valves is to stop blood from flowing backwards
Name 4 parts of the blood
Plasm
White blood cells
Red blood cells
Platelets
What does plasma transport
Transports:
- soluble digestion products (e.g. Glucose) from the small intestines to other organs
- carbon dioxide (produces by aerobic respiration) from the organs to the lungs to be breathed out
- the waste product urea from the liver to the kidneys to be urinated
What do red blood cells do
Transport oxygen from the lungs to the body cells
3 adaptations of red blood cells
- they contain haemoglobin
- no nucleus
- dimples-gives a greater surface area-oxygen diffuses in and out rapidly
What are white blood cells
They form part of the immune system for example by making antibodies
What do white blood cells contain
They contain a nucleus this contains DNA
which instructs the white blood cells what they need to do their jobs
What are platelets
Tiny fragments of cells and their job is to help the blood to clot
What is cardiovascular disease
Diseases of the heart and blood vessels
The are not infectious
Communicable diseases
Can be spread from person to person e.g. cold, chickenpox
How are communicable diseases spread
By pathogens eg bacterial or viruses
Non-communicable diseases
Cannot be passed from person to person e.g. Diabetes
What effects your health
Poor diet
Stress
Working with harmful chemicals
Upper/lower epidermis
Very thin cells
Protects the surface of the leaf
Transparent-allows light to pass through
Waxy cuticle
Covers the upper epidermis
Reduces the evaporation of water-helps prevent lead from drying out
Stomata
Tiny pores on lower epidermis
Allows carbon dioxide to enter the leaf and oxygen to leave
Helps control amount of water vapour the can pass out of the leaf
Where are Guard cells found
Found on either side of stomata
Palisade mesophyll
Packed full of chloroplasts-needed for photosynthesis
Spongy mesophyll
Full of air spaces-allows carbon dioxide and oxygen to diffuse
Xylem tissue in a leaf
Transports water from the roots to the stem and the leaves
Phloem tissue in the leaf
Transports dissolved sugars.
