Unit 2- organisation Flashcards
What is an enzyme
A catalyst which increases the speed of reaction without being changed or used up , they convert food into small soluble molecules that can be absorbed into the bloodstream
What happens if an enzyme gets too hot/
Bonds holding enzyme together will break, changes shape of enzymes active site so substrate won’t fit any more, enzyme is now denatured
What breaks down starch and what does it turn into
Amylase, simple sugars
What breaks down protein and what does it turn into
Protease, amino acids
What breaks down lipids (fats) and what does it turn into
Lipase , glycerol and fatty acids
Where is amylase made
Salivary glands, pancreas, small intestine
Where is protease made?
Stomach, pancreas, small intestine
Where is lipase produced
Pancreas, small intestine
Function of bile
Neutralises stomach acid (as it is alkaline) and emulsifies fat to form small droplets which increases the surface area increases rate of lipid digestion
Where is bile produced
Liver
Where is bile stored
Gall bladder
Function of stomach
Produce hydrochloric acid, pummels food with muscular walls
What does hydrochloric acid do
Kill bacteria, gives right PH for protease enzyme
Test for sugars (glucose)
Benedict’s
What colour will sugar turn in food test
Starts = blue
Ends =Yellow/orange/red
What is the test for starch and what colour will it go
Iodine,
Starts = orange
End = blue black
What is the test for protein and colour does it turn
Biuret
Starts = blue
End= purple
What is the test for lipids and colour does it turn
emulsion
Starts= Clear
Ends = cloudy
Where is the lungs
In the thorax
Name parts of the lungs
Trachea (windpipe), bronchus , alveoli, intercostal muscles, diaphragm
What is the function of alveoli
Carry’s out gas exchange from high to low concentration
Function of valves
Prevent back flow of blood
4 chambers of the heart
Right atrium , right ventricle, left atrium , left ventricle
Function of arteries .
Carry blood under pressure away from heart
Function of capillaries
Supply oxygen and food and take away waste like co2
Function of veins
Carry blood to heart
Characteristics of an artery
High pressure, thick muscular walls, small lumen
Characteristics of capillaries
One cell think walls, very small lumen
Characteristics of veins
Low pressure, valves, large lumen
Function of red blood cells, how are they adapted
Carry oxygen= biconcave shape , large surface area, contain haemoglobin
Function of white blood cells
Defend against infection, engulf unwelcome microorganisms, ingest the pathogens, produce antibodies, do have a nucleus
Function of platelets
Help blood clot, no nucleus
What are platelets
Small fragments of cells
Function of plasma
Carries many substances such as co2, glucose, proteins, antibodies
What is coronary heart disease
When the coronary arteries that supply blood to heart gets blocked by layers of fatty material building up, arteries will then become narrower so blood flow is restricted and there’s a lack of oxygen to heart
What are stents
Tubes that are inserted inside arteries, they keep them open so blood can pass through and the heart will remain beating
Advantages and disadvantages of stents
Effective for long time , quick recovery time
Rick of infection during surgery, risk of patient developing blood clot near stent
What are statins
Drugs that Reduces cholesterol in the blood so arteries are at less risk of being blocked
Advantages and disadvantages of statins
A- reduce risk of strokes/heart attacks, may also prevent other diseases
D- long term drug that must be taken regularly, should not be taken if pregnant or breastfeeding or people with liver disease
What are artificial hearts
Mechanical devices that pump blood for a person who’s heart has failed, usually temporary
What is a communicable disease
Those that spread from person to person. Measles and malaria are examples
What are non communicable diseases
are those that cannot spread between people, usually last longer and get worse slowly. Asthma, cancer and coronary heart disease is an example
Risk factors for non communicable diseases
Consumption of alcohol, smoking/ drugs, exposure to certain substances or radiation
What is cancer caused by
Uncontrolled cell growth and division
What is transpiration
Is the loss water caused by evaporation and diffusion in the leaves
Factors affecting transpiration
Light intensity , air flow, humidity
Function of guard cells
Open and close stomata so gases can be exchanged for photosynthesis
Where is protein digested in human digestive system
Stomach
Describe how and where starch is broken down
- Broken down into maltose by enzyme amylase
- salivary glands release saliva containing amylase into the mouth for digestion
-amylase is also made in the pancreas and gets released into the small intestine where starch can further be digested
Stage 1 of cell cycle
DNA is replicated to form to form copies of each chromosome and mitochondria is increased
Stage 2 of cell cycle
Chromosomes pulled and moved to each end of the cell, the nucleus also divides
Stage 3 of cell cycle
Cytoplasm and cell membrane divide to form two identical cells
Function of liver
Produces bile which emulsifies fat and makes enzymes the correct PH
Gets rid of lactic acid as this could be the poisonous to the body
Removed toxins which are poisonous to body
Types of defences responses
Mechanical (thorns and hairs) and chemical (poisonous berries)
What enzyme works in the stomach
Protease
Apart from digestion what is another function of hydrochloric acid in the stomach
To kill pathogen
What smaller molecules are enzymes made of
Amino acids
Explain how lock and key theory works
-Substrate binds to the active site of the enzyme
-because the shape of the active site and substrate fit together
-a chemical reaction occurs to produce smaller molecules
Advantage of a double circulatory system
Blood can travel rapidly to the body cells delivering oxygen that they need
What does the heart mostly consist of
Muscle tissue
How many chambers does the heart have
4
Function of vena cava
Brings in deoxygenated blood from the body
How does the blood get from the heart to the lungs
Pulmonary artery
What pumps the blood from the heart to the body
Aorta
Why does the left side of the heart have thicker more muscular walls
The left ventricle pumps blood around the entire body so it needs to supply a greater force
Purpose of the coronary arteries
Provide oxygen to the muscle cells of the heart
Where are the coronary arteries
Branch out of the aorta and spread out into the heart muscle
What is the natural resting heart rate controlled by
The pacemaker
Function and adaptation of a leaf
Lots of air gaps between cells so gas can easily diffuse through to next layer
Function and adaptation of palisade mesophyll
Site of photosynthesis, contain lots of chloroplasts
Function and adaptation of the upper epidermis layer
Cells are almost transparent to allow sunlight to get through to chloroplasts
Why does the top layer have a waxy cuticle layer
To prevent water loss
Compare the structure of a xylem and a phloem cell
The xylem is made of dead cells however the phloem is made of living cells.
Xylem does not contain chloroplasts and the phloem do contain chloroplasts
Xylem contain lignin however phloem doesn’t not contain lignin. They are both made of cells
Phloem cells have pores xylem cells do not.
Xylem does not contain cytoplasm but phloem does
Name the cell that controls the rate of water loss
Guard cells
Why is the rate of water loss at midnight lower than at 12:00
Stomata are closed because there’s no light
Why is the rate of water loss at midnight lower than at 12:00
Stomata are closed because there’s no light
Why is the rate of water loss at midnight lower than at 12:00
Stomata are closed because there is no light
Definition of health
State of physical and mental well being
Physical defence systems of plants
Contain a cell wall made of cellulose which is hard to penetrate
Leaves contain layer called waxy cuticle which is also difficult to penetrate
Bark is a barrier to microorganisms
Chemical defence systems in plants
-Release antibacterial chemicals which kill bacteria and prevent them attacking plant
-release poisons to deter herbivores from grazing on plant
Mechanical defence systems of plants
-Sharp thorns directly protect plant from being eaten by a herbivore
-hairs which irritate mouths making plant difficult to eat
-mimicry (dead nettle looks like it may be a stinging nettle but actually has no sting)
What will scientists have to do to kill the development of new strains
New antibiotics
What is a tissue
A group of cells with a similar structure and function
What is an organ
Group of tissues working together for a specific function
What is an organ system
Group of organs working together
What is the process of digestion
Large food molecules are broken down into small molecules by enzymes. The small molecules are absorbed into the bloodstream
Function of mouth in digestive system
Food is chewed, Amylase in the saliva digest the starch into smaller sugar molecules
Function of stomach in digestive system
Protease begins the digestion of proteins, hydrochloric acid helps enzymes digest proteins churning action of stomach muscles turns food into a fluid increasing the surface area for enzymes to digest
Function of pancreas during digestion
Releases amylase, protease and lipase
What happens in the small intestine to the food molecules
Small food molecules are absorbed by the bloodstream either by diffusion or active transport
Role of large intestine in digestive system
Where water is absorbed
What does a lipid molecule consist of
Consist of a molecule of glycerol attached to three molecules of fatty acids
What happens if Ph is too high or low for an enzyme to work
The active site denatures if conditions are too acidic or alkaline, this means the substrate won’t fit and so cannot become broken down
How to make a food sample
Grind up the food using a mortar and oestre to make a paste, add distilled water to paste and stir so chemicals dissolve in water , filter solution to remove food particles
What colour is iodine solution and how many drops should you add to your food solution roughly
Orange, a few (3)
What colour is Benedict’s solution and how many drops should you add to your food sample roughly
Blue , 10
Negative of Benedict’s test
Only work for certain sugars (glucose)
Method for Benedict’s test
-add 10 drops of Benedict’s solution
-place test tube into a beaker containing hot water from kettle
-Leave for 5 mins
What colour is the biuret solution
Blue
Why should you not filter lipids before testing
Lipids can stick to filter paper
Process of testing for lipids
Do not filter solution
Add distilled water and ethanol to food sample
Shake
Danger for ethanol in lipids test
Make sure no flames present as ethanol is flammable
Risk factors for cardiovascular diseases
-diet = a high fat and low vegetables increases cholesterol in blood, high salt diet can increase blood pressure
-smoking = also increases risk for lung cancer
Effects of smoking on an unborn baby
Risk of miscarriage or premature birth or underweight baby
Effects of drinking alcohol on unborn baby
Causes fatal alcohol syndrome which can cause learning difficulties or disabilities
Effects of drinking alcohol on adults
Increase risk of liver cirrhosis and liver cancer
Lead to memory loss and addiction
Risk factors of type 2 diabetes
Lead to blindness or require amputation of limb
Obese people have much bigger risk of developing type 2 diabetes
Natural risk factors of cancer
-Radon in your system can develop lung cancer
Risk factors for cancer
-smoking (lung cancer)
-genetic (breast cancer)
-UV light (skin cancer)
-alcohol (throat cancer)
Adaptation of the trachea during gas exchange
Rings of cartilage prevent the trachea from collapsing during inhalation
Adaptations of alveoli for gas exchange
-millions of alveoli mean that the lungs have a large surface area
-thin walls so diffusion path is shorter
-good blood supply which mean concentration gradient is as steep as possible
What is epidemiology
Studying the patterns of disease to determine risk factors
What is causal mechanism
When scientists look for a possible mechanism by which the factor could be the likely cause.
Where in the heart is the pacemaker found
Right atrium
Explain lock and key theory
Substrate binds to active site of enzyme
Because shape of active sit and substrate are complimentary
Chemical reaction occurs to produce smaller molecules
Advantages and disadvantages of heard transplant for coronary heart disease
A = improved quality of life and can be lifesaving
D= few donor hearts available, recovery time is long, risk of rejection be the body’s immune system, expensive operation and aftercare
Advantages and disadvantages of replacement heart valves to improve circulation to treat coronary heart disease
A= restore blood flow through the heart, less risk of complications in surgery than heart transplant
D=biological valves may wear out, blood clots may stick to mechanical valves so anti blood clotting drugs need to be taken however this increases risk of further illness
How might different diseases interact
-defects in the immune system mean than an individual is more likely to suffer from infectious diseases
-viruses living in cells can be the trigger for cancers
-immune reactions initially caused by a pathogen can trigger allergies such as skin rashes and asthma
-severe physical health can lead to depression and other mental illness
How does temperature, humidity, and light intensity affect transpiration
Temp= increases because more evaporation so the rate of diffusion of water from inside the leaf to outside increases
Humidity= decreases as reduced concentration of water molecules outside the leaf so rate of diffusion of water from inside the leaf to outside increases
Light intensity = generally increases the number of open stomata so rate of diffusion of water from leaf to outside increases
