TOPIC B2 Cell Organisation Flashcards
What is a tissue?
A group of similair cells that work together to carry out a function.
What is an Organ?
An organ is a group of different tissues that work together to perform a certain function.
Give an example of an organ:What tissues is it made up of?
STOMACH. Made up of muscular, epithelial and glandular tissues.
What is an organ system?
An organ system is a group of organs working together to perform a function.
Give an example of an organ system:
THE DIGESTIVE SYSTEM. It breaks down and absorbs food.
Organ systems work together to make…
Enitre organisms.
What does the salivary glands do?
Produce amalyse enzyme in the saliva.
What does the liver do?
Produces bile. Bile neutrslises stomach acid and emulsifies fats.
What does the large intestine do?
Absorbs water from undigested food, leaving faeces (poo).
What does the stomach do? (3)
- It pummels the food with its muscular walls.- Produces the protease enzyme “pepsin”- Produces hydrochloric acid to kill bacteria and to give the right PH for protease enzyme to work - PH 2.
What does the pancreas do?
Produces protease, amalyse and lipase enzymes and releases them into the small intestine.
What does the small intestine do? (2)
Produces protease, amalyse and lipase enzymes to complete digestion.Also where the digested food is absorbed out of the digestive system into the blood.
Living things have tons of reactions going on inside their cells. What controls these reactions?
ENZYMES - LARGE PROTEINS.
What do enzymes do?
They speed up reactions inside living things by acting as catalysts.
What is a CATALYST?
A catalyst is a substance which increases the speed of a reaction without being changed or used up in the reaction.
EXPLAIN THE LOCK AND KEY MODEL:
Every enzyme has an active site and a unique shape. The substance involved in the reaction HAS TO FIT into the active site for the enzyme to work.
How does temprature effect the rate of a reaction involving an enzyme?
A higher temprature speeds up the rate at first but if it gets too hot, some of the bonds holding the enzyme together break. This changes the shape of the enzyme’s active site so the substrate won’t fit anymore - the enzyme has denatured.
What is an OPTIMUM TEMPRATURE?
The temprature that the enzyme works best at.
How can PH effect the rate of a reaction involving an enzyme?
If the PH is too high or low, it affects the bonds holding the enzyme together. It changes the shape of the active site and denatures the enzyme.
What is an OPTIMUM PH?
The PH that the enzymes work best at?
INVESTIGATING THE EFFECT OF PH ON ENZYME ACTIVITY:Give the 7 steps:
1) Put a drop of iodine solution into every well of a spotting tile.
2) Place a bunsen burner on a heatproof mat and a tripod and gauze over it. Put a beaker on top and heat the water until it is 35c.
3) Use a syringle to add 1cm cubed of amalyse solution and 1cm cubed of a buffer solution with a PH of 5 to a boiling tube. Put the tube into the beaker of water and wait for 5 mins (with test tube holders)
4) Use a different syringle to add 5cm cubed of a starch solution to the boiling tube and immediently mix the contents of the boiling tube and start a stop clock.
5) Use continous sampling to record how long it takes for the amalyse to break down all of the starch., use a dropping pipette to take a fresh sample from the boiling tube every 30 seconds and put a drop into a well.
6) When the iodine solution remains browny orange, there is no longer starch.
7) Repeat it with buffer solutions of different pH values to see how pH effects the time taken for the starch to be broken down.
Rate is a measure of…
How much something changes over time.
FORMULAE TO FIND RATE OF REACTION:
RATE OF REACTION = 1000 DIVIDED BY TIME.
Digestive enzymes break big molecules down into smaller ones. Give examples of BIG MOLECULES:
- FATS.- STARCH.-PROTEIN.
Give an example of a CARBOHYDRASE (Something that breaks down starch):
Amalyse.
Where is amalyse made? (3)
Salivary Glands.Pancreas.Small Intestine.
Where does amalyse work? (2)
MOUTH.SMALL INTESTINE.
What does PROTEASE BREAK DOWN?
Proteins.
What does amalyse break down starch into?
Sugar.
What does PROTEASE break down protein into?
Amino Acids.
Where are Protease made? (3)
- Stomach.- Pancreas.- Small Intestine.
Where do Protease work (2)
StomachSmall Intestine
What do Lipase break down?
LIPIDS - FATS.
Where are Lipase made? (2)
PancreasSmall Intestine
Where do Lipase work?
Small Intestine
What do Lipids turn into?
Glycerol and fatty acids.
Where is Bile produced?
In the liver.
Where is Bile stored?
In gall bladder before it is released into the small intestine.
Is Bile Alkaline?
Yes, it neutralises hydrochloric acid (from the stomach) and makes conditions alkaline.
The enzymes in the small intestine work best in….
alkaline conditions.
Bile emulsifies Fats. What does this mean?
It breaks the fat down into tiny droplets. Gives a bigger surface area of fat for lipase to work on = makes digestion faster.
4 steps to prepare a food sample:
1) Get a piece of food and break it up using a pestle and mortar.
2) Transfer the ground up food to a beaker and add some distilled water.
3) Give the mixture a good stir with a glass rod to dissolve some of the food.
4) Filter the solution using a funnel lined with filter paper. This will get rid of the solid bits of food.
What test is used for sugar?
BENEDICT’S TEST.
What test is used for starch?
IODINE SOLUTION.
What test is used for proteins?
BIURET TEST.
What test is used for lipids?
SUDAN 111 TEST.
How do you know if there is sugar in a solution?
The solution will change from the normal blue colour to green, yellow or brick red - depending on how much sugar is in the food.
How do you know if there is starch in a solution?
The colour of the solution will change from browny orange to black or blue-black.
How do you know if there is protein in a solution?
The solution will change from blue to pink or purple.
How do you know if there is lipids in a solution?
The mixture will seperate out into two layers, the top layer will be bright red.
Give the 4 stages of the BENEDICT’S TEST FOR SUGAR:
1) Prepare a food sample and transfer 5cm cubed to a test tube.2) Prepare a water bath so that it’s set to 75.c.
3) Add 10 drops of Benedict’s solution to the test tube using a pippette.
4) Place the test tube into the water bath with a test tube holder, leave it there for 5 mins. Look at the colour.
Give the 2 stages of the IODINE SOLUTION FOR STARCH:
1) Make a food sample and transfer 5cm cubed to a test tube.2) Add a few drops of iodine solution and gently shake the tube to mix the contents. CHECK COLOUR.
Give the 2 stages of the BIURET TEST FOR PROTEINS:
1) Prepare a sample of your food and transfer 2cm cubed to a test tube.
2) Add 2cm cubed of biuret solution to the sample. Mix the contents of the tube by gently shaking. CHECK COLOUR.
Give the 2 stages of the SUDAN 111 TEST FOR LIPIDS:
1) Prepare a food sample but don’t filter it and transfer 5cm cubed to a test tube.
2) Add 3 drops of SUDAN 111 Stain solution to the test tube and gently shake.
3) Check colour.
The air that you breathe in goes through the…
Tranchea then it passes through the bronchi then the bronchioles and ends up in the alveoli.
Alveoli in the lungs are surrounded by blood capillaries. Explain.
Blood comes into the lungs through the capillaries. Contains a lot of carbdon dioxide and very little oxygen.
How does diffusion work in the alveoli?
The oxygen diffuses out of the air in the alveolus (where there is a high concentration) into the blood (where there is a lower concentration).
What is the breathing rate?
How fast a person moves air in and out of their lungs.
How to calculate breaths per minute?
number of breaths divided by number of minutes.
What 3 things is the circulatory system made up of?
Blood VesselsBloodHeart
What is a double circulatory system?
Two circuits joined together.
What happens in the first circuit in the heart?
The heart pumps deoxygenated blood to the lungs . The blood picks up oxygen in the lungs. Oxygenated blood returns to the heart.
What happens in the second circuit in the heart?
The heart pumps oxygenated blood around all the other organs of the body. This delivers oxygen to the body cells. Deoxygenated blood returns to the heart to be pumped out to the lungs again.
What 4 chambers make up the heart?
RIGHT ATRIUM LEFT ATRIUM
RIGHTVENTRICLE LEFT VENTRICLE
Mostly made of muscle tissue as this helps to pump blood around body.
Blood flows into the two atria from…………..The atria pump the blood into the……..The ventricles pump the blood out of the heart.Blood from right ventricle goes through……Blood from left ventricle goes through…..The blood then flows to the organs through…….The atria fill again. CYCLE RESTARTS.
Blood flows into the two atria from the VENA CAVA AND THE PULMONARY VEIN.The atria pump the blood into the VENTRICLES.The ventricles pump the blood out of the heart.Blood from the right ventricle goes thorugh THE PULMONARY ARTERY TO THE LUNGS.Blood from the left ventricle goes through the AORTA TO THE REST OF THE BODY.The blood then flows to the organs through ARTERIES and RETURNS THROUGH THE VEINS.
What do the valves stop the blood doing?
From flowing backwards.
Where does the heart get oxygenated blood from?
Arteries called CORONARY ARTERIES. These branch of the aorta and surround the heart.
Your resting heart rate is controlled by….
a group of cells in the right atrium wall. They act as a pacemaker and tell the heart when to pump blood.
A pacemaker that doesn’t work properly causes irregular heartbeat. What can help this?
An artificial pacemaker can be used to keep the heart beating regularly.
Arteries carry blood…
Away from the heart at high pressure.
How are arteries adapted to their job? (3)
1) They have thick layers of muscle to make them strong.
2) Artery walls are strong and elastic.
3) Walls are thick compared to the size of the hole down the middle
Arteries branch into…
capillaries.
Where do capillaries carry blood to?
They carry the blood really close to every cell in the body to exchange substances with them.
How are capillaries adapted to their job? (3)
1) They have gaps in their walls so substances can diffuse in and out.2) Their walls are usually only one cell thick which means diffusion is very fast because there is only a short distance for molecules to travel.
3) Supply food and oxygen and take away waste like CO2.
Capillaries join up to form…
Veins.
The blood in capillaries is at….
lower pressure so the walls don’t need to be as thick as arteries.
Veins have a bigger……… than artieries.
Bigger lumen - this helps blood flow despite the lower pressure.
Why do veins have valves?
To keep the blood flowing in the right direction.
What is the rate of blood flow?
The amount of blood that passes through a blood vessel in a given time.
FORMULAE FOR RATE OF BLOOD FLOW:
VOLUME OF BLOOD DIVIDED BY NUMBER OF MINUTES.
What is the job of RED BLOOD CELLS?
To carry oxygen from the lungs to all the cells in the body.
Give 3 ways that RED BLOOD CELLS are adapted to their job:
1) Their shape gives them a large surface area for absorbing oxygen.
2) They contain HAEMOGLOBIN which allows them to carry the oxygen.
3) They don’t have a nucleus = more space for oxygen.
What is the job of WHITE BLOOD CELLS?
To defend against infection - they are part of our immune system.
How are WHITE BLOOD CELLS adapted to their job?
They can produce antibodies and antitoxins.
What are Platelets?
Small fragments of cells that helps your blood to clot as a wound.
Give 2 advantages of PLATELETS:
1) They stop your blood from pouring out.2) It stops micro organisms getting in.
What is PLASMA?
A pale straw coloured liquid that carries everything in the blood.
What 5 things do PLASMA carry?
- Red, white blood cells and platelets.- Nutrients e.g. glucose and amino acids.- Waste products e.g. carbon dioxide and urea.- Hormones.- Protein.
What are Cardiovascular diseases?
Diseases of the heart or blood vessels.
What is Coronary heart disease?
When layers of fatty materials (fatty deposits) build up in the coronary arteries and cause arteries to become narrow.
Why is Coronary heart disease dangerous?
It reduces the blood flow to the heart muscle which means less oxgen gets to the heart = heart attack.
What are Stents?
Stents are tubes that are put inside the coronary arteries by surgery. They keep the arteries open so blood can reach the heart muscles.
Give 2 advantages of Stents:
- Effective for a long time.-Recovery time from surgery is quite quick.
Give 3 disadvantages of Stents:
- Could have a heart attack during surgery.- Blood clot near the stent.- Getting an infection after surgery.
What is Cholesterol and how does it cause coronary heart disease?
It is a lipid your body needs. However, too much can cause fatty deposits to build up inside arteries.
What are STATINS?
Drugs that reduce the amount of cholesterol in the blood which slows down the rate of fatty deposits forming.
Give 3 advantages of STATINS:
- Reduce the risk of strokes, heart attacks and coronary heart disease.-Some studies show it may help prevent some other diseases.- They reduce the bad cholesterol and can increase the good/HDL cholesterol in your bloodstream
Give 3 disadvantages of STATINS:
- Must be taken regularly over time, people may forget.- Could cause side effects etc, headaches.- Takes time to work.
What is a heart transplant?
When a person’s heart is replaced by a donor heart (someone who has recently died).
You would need a heart transplant if someone has heart failure; What is heart failure?
When a heart can’t pump enough blood.
What would happen if a donor heart wasn’t avaliable?
Doctors may fit an artificial heart - a machine that pumps blood around the body.
Give an advantage of an artificial heart:
They are made from metals or plastic so it’s less likely that the immune system will attack them.
Give 4 disadvantages of an artificial heart:
- Surgey to fit one can lead to bleeding and infection.- They don’t work as well as healthy natural ones.- Blood doesn’t flow through them as smoothly - causes blood clots and leads to strokes.- Patient has to take drugs to thin their blood so they may bleed more than usual if they have an accident.
Give 2 ways a heart valve could be damaged:
- Heart attacks, infection or old age may cause the valve to stiffen so it won’t open properly.- A valve may be leaky and blood will flow in both directions.
What can heart valves be replaced with?
Biological valves - valves from humans, or other mammals - pigs cows etc.
Apart from biological valves, what can faulty heart valves be replaced with?
Mechanical valves - man made valves.
Define Health:
The state of physical and mental wellbeing.
Define Communicable Diseases:
Diseases that can be spread from person to person or between animals and people.
Define Non Communicable Diseases:
Diseases that cannot spread between people or between animals and people.
The immune system helps to fight pathogens, why would it be bad if someone has an issue with their immune system? Give an example.
They are more likely to suffer with communicable diseases. They may get flu because their body can;t defend itself against that pathogen.
How can a physical health problem turn into a mental health problem?
Someone may be depressed if they can’t carry out everyday activities because of ill health.
Give 3 other factors that can affect your health:
- Poor diet.- Being under too much stress.- Life situation - e,g, how easily you can access medicine.
What are risk factors?
Risk factors are things that are linked to an increased chance of getting a certain disease.
3 types of risk factors:
- Lifestyle - e,g, how much exercise someone does.- Substances in the environment e.g. pollution.- Substances in a person’s body.
Globally, non communicable diseases are more common in developed countries. Why?
Because people in developed countries can afford to buy high fat food.
Nationally, obesity, type 2 diabetes etc are common in poorer countries. Why?
Because people in poorer areas are more likely to smoke and have a poor diet.
Give 2 examples where risk factors can cause a disease directly:
- Smoking can cause lung disease as it damages the walls of arteries and the lining of lungs.
- Drinking too much alcohol can damage the brain and liver.
How would a non communicable disease be costly? (2)
If a person has to give up work, their family will receive less income.
The cost to the NHS of researching and treating these diseases is huge.
What causes cancer?
Uncontrolled cell growth and division.
Tumours can be benign or malignant. Give 3 facts about BENIGN TUMOURS:
- They stay in one place (usually within a membrane).
- They don’t invade other parts of the body.
- Not dangerous and the tumour isn’t cancerous.
Tumours can be benign or malignant. Give 3 facts about MALIGNANT TUMOURS:
- Can spread.
- The cells can break off and travel in the bloodstream.
- The cells get into healthy tissues and form secondary tumours.FATAL.
Give 4 lifestyle risk factors:
1) Smoking. - Lung cancer.2) Obesity. - Kidney cancer.3) Viral Infection. - Certain types of cancer.4) UV Exposure. Skin cancer.
Give 2 genetic risk factors:
1) Genes are inherited.
2) Faulty genes may be inherited so your more likely to get cancer.
People are now likely to survive cancer. Why? (4)
- Treatments have improved.
- Doctors can diagnose it earlier.
- More people are being tested for cancer.
- People know more about the risk factors for cancer.
Plant cells are organised into…
Tissues and organs.
Examples of Plant tissues:Epidermal tissue…
covers the whole plant.
Examples of Plant tissues:Palisade Mesophyll Tissue…
part of the leaf where most photosynthesis happens.
Examples of Plant tissues:Spongy Mesophyll Tissue….
part of the leaf that has big air spaces which allows gases to diffuse i and out of cells.
Examples of Plant tissues:Xylem and Phloem…
transport things like water, mineral ions and food around the roots, stems and leaves.
Examples of Plant tissues:Meristem tissue….
Found at the growing tips of shoots and roots.
First layer of plant. Upper Epidermis. Second Layer of plant: Palisade Layer Third layer of plant: Spongy Mesophyll. Fourth Layer Lower Epidermis Fifth Layer: Stomata Sixth Layer:Xylem and Phloem
This layer is transparent and lets light through to the palisade layer.
Has lots of chloroplasts. Near to the top of leaf to get more light.
Contains air spaces which increase the rate of diffusion of gases.same as upper epidermis.These let gases diffuse into and out of the leaf. They are opened and closed in response to the environment. Controlled by guard cells.These bring water and nutrients to the leaf and take away glucose produced by photosynthesis. Also, support the leaf.
Phloem transport transport….
Food.
Phloem tubes are made of….
stretched out living cells.
Why do Phloem cells have end walls between cells that have pores?
To allow cell sap to flow through.
Plants make food substances in their leaves. Phloem tubes transport these around the plant for use or storage. What is this process called?
Translocation.
Xylem tubes are made of…
dead cells.
Are their end walls between XYLEM TUBES?
No. They are strengthened with a material called lignin.
What do Xylem Tubes carry?
They carry water and mineral ions from the roots to the stem and leaves.
The movement of water from the roots through the xylem and out of the leaves is called….
The transpiration stream.
What is Transpiration caused by?
Evaporation and diffusion of water from a plant’s surface (mainly the leaves).
Give the 3 steps of TRANSPIRATION:
1) Water evaporates from leaves and diffuses into the air.2) This creates a shortage of water in the leaf so more water is drawn through the xylem cells.3) There is a constant stream of water through the plant. TRANSPIRATION STREAM.
List the 4 main things that affect TRANSPIRATION RATE:
-Air flow.- Temperature.- Humidity.- Light Intensity.
How does Air flow effect transpiration rate?
The more windy it is = the faster it happens. Fast moving air means that the water vapour around the leaf is swept away so there is a higher concentration of water vapour inside the leaf compared to outside = WATER WILL DIFFUSE OUT QUICKLY.
How does Temperature effect transpiration rate?
The warmer it is, the faster transpiration happens because the water particles have more energy so they evaporate and diffuse out of the stomata faster.
How does Humidity effect transpiration rate?
If the air is humid there’s a lot of water in it already so there isn’t much of a difference between outside and inside of the leaf. Diffusion will not happen very fast = the drier the air around a leaf, the faster transpiration happens.
How does Light Intensity effect transpiration rate?
The brighter the light, the greater the transpiration rate.Photosynthesis can’t happen in the dark so stomata begin to close as it gets darker and when they are closed, very little water can escape.
Guard cells control…
Gas Exchange and Water Loss.
Stomata are surrounded by…
guard cells.
Why do Guard cells change shape?
To control the size of the stomata
When the plant has lots of water, the guard cells….
fill with it and get fat. This makes the stomata open so gases can be exchanged for photosynthesis.
When the plant is short of water the guard cells…
lose water and become floppy so the stomata closes. This helps to stop too much water vapour escaping.
Why are there usually more stomata on the bottoms of leaves than on the tops?
This is because the lower surface is cooler so less water gets lost.
What are cells?
The basic building blocks that make up all living organisms.
Give 3 examples of tissues in mammals (like humans):
1 - Muscular tissue which conttacts to move whatever it’s attached to.2 - Glandular tissue - which makes and secretes chemicals like enzymes and hormones.3 - Epithelial tissue which covers some parts of the body e.g. inside of the gut.
What does the Gall Bladder do?
It is where bile is stored before it’s released into the small intestine.
When someone loses a lot of blood, the heart can…
Still pump the remaining red blood cells around as long as the volume of their blood can be topped up.
What is artificial blood?
A blood substitute (e.g. a salt solution “saline”) which is used to replace the lost volume of the blood.
Give an advantage of artificial blood:
Can help keep people alive even if they lose 2/3 of their red blood cells - should give the patient enough time to produce new ones. If not, the patient will need a blood transfusion.
How can you estimate the rate of transpiration? Why?
By measuring the uptake of water by a plant. This is because you can assume that water uptake by the plant is directly related to water loss by the leaves (transpiration).
