B2 - Organisation Flashcards
What are cells?
Building blocks that make up all living organisms
What is a tissue?
Group of similar cells that work together to carry out a particular function and it can include more than 1 type of cell
What are organs?
Group of different tissues that work together to a certain function
What are organ systems?
A group of different tissues that work together to perform a certain function
What are catalysts?
A substance which increases the speed of a reaction, without being changed or used up in the reaction
Why are enzymes produced in our body?
To speed up digestion and prevent the rising of our body temperatures which could damage cells
What are enzymes?
Biological catalysts made out of large proteins and chains of amino acids which are folded into unique shapes. They are used to speed up a reaction without being used up
Where does the reaction take place in enzymes?
Active Site
What is an Active Site on an enzyme?
A unique shape that fits onto the substance
What is the ‘lock and key’ model?
Where the specific enzyme can only bind to certain substances (e.g protein) and if doesn’t they won’t be catalysed
What is the ‘included fit’ model?
The active site changes shape a little as the substrate binds to get a tighter fit
What is the substance that an enzyme acts on?
Substrate
How does temperature affect enzyme-catalysed reactions?
The rate
What is the optimum body temperature for enzymes?
37 (body temperature)
Do different enzymes have different optimum temperatures?
yes
How does pH affect enzymes?
The pH interferes with the bonds holding the enzyme together which changes the shape of the active site and denatures the enzyme
Can enzymes die?
No, they become DENATURED
How do you calculate the rate of reaction?
1000/time s^-1
OR (for measuring how much something changes over time)
change/time cm^3 s^-1
Where are enzymes used?
In the digestive system
Why do we need enzymes to break down nutrients?
- Because they are too big pass through the walls of the digestive system
- Would take too long to do
Where is amylase produced? (carbohydrase)
- Salivary glands
- Pancreas
- Small intestine
Where are proteases made?
- Stomach
- Pancreas
- Small Intestine
Where are lipase made?
- Pancreas
- Small intestine
What are carbohydrates converted into by amylase?
Sugar molecules and Maltose
What are proteins broken down into by protease?
Amino acids
What are fats broken into down by lipase?
Fatty acids and Glycerol
What is bile?
A green substance produced by the liver
Where is bile stored?
Gall bladder before it is released into the small intestine when being used
Why do we need bile?
The hydrochloric acid makes the pH too acidic for enzymes in the small intestine to work properly. Bile is alkaline - it neutralises the acid and makes conditions alkaline
What does bile do?
It emulsifies fat and breaks them into tiny droplets which gives a bigger surface area of fat for the enzyme lipase to work on (making digestion faster)
Name in order all the organs in the digestive system
1) Mouth
2) Salivary Glands
3) Oesophagus
4) Stomach
5) Pancreas
6) Liver
7) Gall bladder
8) Small intestine (duodenum and ileum)
9) Large Intestine (colon and rectum)
10) Rectum
11) Anus
Mouth
Where food enters the alimentary canal and digestion begins
Salivary glands
Produce saliva containing amylase
Oesophagus
Muscular tube which moves ingested food to the stomach
Stomach
Muscular organ where digestion continues
Pancreas
Produces digestive enzymes
Liver
Produces bile
Gall bladder
Stores bile before releasing it into the duodenum
Small intestine - duodenum
Where food is mixed with digestive enzymes and bile
Small intestine - ileum
Where digested food is absorbed into the blood and lymph
Large intestine - colon
Where water is reabsorbed
Large intestine - rectum
Where faeces are stored
Large intestine - anus
Where faeces leave the alimentary canal
What test should you use to test for sugars?
Benedict’s Test
Benedict’s Test method
Add Benedict’s reagent to the food and boil in a water bath.
What should you use to test for starch?
Iodine
Iodine test method
Add iodine reagent to the food.
What should you use to test for proteins?
Biuret (a mixture of sodium hydroxide and copper sulfate)
Protein test method
Add Biuret reagent to the food.
What should you use to test for fats?
Ethanol/cooking paper
Lipid test method
Add ethanol to the food to dissolve the fat then add water.
Sugar test colours
i: blue
p: red
Starch test colours
i: yellow/brown
p: blue/black
Protein test colours
i: blue
p: lilac/purple
Lipids test colours
i: colourless
p: white emulsion
Respiratory system
- Diaphragm
- Oesophagus
- Bronchiole
- Bronchus
- Alveoli
- Pleural membranes
- Heart
- Rib
- Intercostal muscle
What are the lungs protected by?
Ribcage
Where does air flow down?
Trachea
What are the lungs surrounded by?
Pleural membranes
What are bronchi?
The 2 tubes going into each lunch splitting from the trachea
What are bronchioles?
Smaller branches of bronchi
What are alveoli?
There are millions of alveoli which are little air sacs surrounded by a blood network of blood capillaries
Where does gas exchange happen?
Inside the alveoli
Explain the gas exchange process in alveoli
- Blood passing next to alveoli returned from the body which are de-oxygenated (lots of CO2)
- Oxygen diffuses out of the alveolus and into the blood
- CO2 diffuses out from the blood and into the alveolus
Why do alveoli have than walls?
Easier to diffuse making the process quicker and efficient
How do you work out breaths per minute?
Breaths/Minutes
Why does the body have a double circulatory system?
More pressure and more efficient
What is the circulatory system made out of?
The heart, blood vessels and blood
Parts of the heart
Atrium Ventricles Pulmonary vein/artery Aorta Vena Cava Pacemaker Coronary artery
What are the 4 chambers of the heart?
Right Atrium, right ventricle, left atrium and left ventricle
Stages of the heart pump
1) Blood flows into the 2 atria from the vena cava and pulmonary vein
2) The atria contract, pushing blood into the ventricles
3) Ventricles contract, forcing blood into the pulmonary artery and the aorta, and out of the heart
4) The blood flows to the organs through arteries, and returns through veins
5) The atria fill again and the whole cycle starts over
Which parts of the heart deal with de-oxygenated blood?
Vena Cava
Right Atrium
Right Ventricle
Pulmonary Artery
Which parts of the heart deal with oxygenated blood?
Pulmonary Vein
Left Atrium
Left Ventricle
Aorta
What is the pacemaker?
A group of cells that control your heart rate which produce a small electric pulse which spreads to the surrounding cells causing them to contract
What can be used to help the pacemaker of the heart?
An artificial pacemaker
Where is the pacemaker?
Right Atrium
What are the 3 blood vessels?
Arteries, capillaries, veins
Arteries
- Carry blood away from the heart
- Pumps blood at high pressure so the artery walls are strong and elastic
- The walls are thick compared to the size of the hole down the middle (“lumen”)
- They contain thick layers of muscle to make them strong, and elastic fibres to allow them to stretch and spring back
Capillaries
- Involved in the exchange of materials at the tissue
- Really tiny, too small to see
- Carry blood really close to every cell to exchange substances
- permeable walls so they can diffuse in and out
- supply and collect waste from tissues
- walls only 1 cell thick so rate of diffusion increases
Veins
- Carry blood to the heart
- Low pressure so the walls aren’t that thick
- Bigger lumen than arteries
- Valves to keep blood moving in the right direction
Blood cell function
To carry oxygen from the lungs to the heart
How are blood cells shaped?
Biconcave disc to give a large surface area for absorbing oxygen
Why do red blood cells not have a nucleus?
Allows more space for oxygen
Why are red blood cells red?
Haemoglobin which binds to oxygen to form haemoglobin
Phagocytosis
White blood cells engulfing pathogens
What are platelets?
- Small fragments of cells with no nucleus
- Help clot blood at a wound
What is plasma?
A substance that carries everything in blood
What does plasma carry?
- Red and white blood cells
- Platelets
- Glucose
- Amino acids
- Carbon dioxide
- Urea
- Hormones
- Protein
- Antibodies and Antitoxins
Coronary heat disease
Coronary arteries that supply blood to the muscle of the heart get blocked by layers of fatty material building up. This causes a lack of oxygen to the heart muscle which can result in heart attack
What are stents?
Tubes that are inserted inside arteries keeping them open, making sure blood can pass through to the heart muscles. This keeps the person’s heart beating
Give some cons to stents
- Risk of infection from surgery
- Thrombosis (a developing blood clot near the stent)
How do fatty acids end up in arteries?
When too much ‘bad’ cholesterol is in your bloodstream
What are statins?
Drugs that can reduce the amount of ‘bad’ cholesterol present in the blood stream. This slows down the rate of fatty deposits
Advantages of statins
- Reduces risk of stroke, chd, and heart attacks
- Increase the amount of ‘good’ cholesterol
- May prevent other diseases
Disadvantages of statins
- Long term drugs
- Headaches
- Takes time
Artificial Heart
- A patient will need heart transplant using donor organs or an artificial heart
- Usually a temporary fix until there is a donor
- Main advantage is they’re less likely to be rejected by body’s immune system
- Can lead to infection and bleeding
Biological or Mechanical Valves
- Fix incorrect blood flow caused by leaky valves which causes an ineffective blood flow
- Replacement valves can be taken from other humans or mammals
- Surgery is less drastic
- Can cause blood clots
Artificial blood
- Saline which is used to replace lost volume of blood
- It’s safe if no air bubbles get in
Health
The state of physical or mental well being
Differences between communicable and non-communicable diseases
- Communicable can be spread from one person to another
- Non communicable cannot be spread and take a long time which get worse slowly
Give some different types of diseases that can interact
1) Targeting immune system
2) Cancer
3) Immune system reactions
4) Mental health
Give some factors that can affect your health
- Balanced life diet
- Stress
- Life situation
Give some risk factors that can increase chance of getting disease
- Smoking
- Alcohol
- Obesity
- Radiation
Why can non-communicable diseases be costly?
- Expensive research
- Expensive treatment
- Family income could be reduced (father or mother)
What are the 2 different forms of cancer?
- Benign
- Malignant
Benign cancer
When the tumour grows until there is no more room. It usually stays in one place rather than invade other tissues. It isn’t too dangerous and isn’t cancerous
Malignant cancer
When the tumour spreads to its neighbouring healthy tissues. Cells can break off and spread to other parts of the body by travelling in the bloodstream. They invade healthy tissues everywhere else and form secondary tumours. They are dangerous and are cancers.
What risk factors are associated with lifestyle?
- Smoking
- Obesity
- UV exposure
- Viral infection
Give some risk factors that can be associated with genetics
- Faulty genes
- Mutations
Epidermal tissue
- Tissue that covers the whole plant
- Covered in tiny waxy cuticle, which helps to reduce water loss by evaporation
- (Upper epidermis) Transparent so that light can pass through
- (Lower epidermis) Little holes called stomata controlled by guard cells
Palisade mesophyll tissue
- Part of the leaf where most photosynthesis happens
- Lots of chloroplasts and near the top where they can get the most light
Spongy mesophyll tissue
- Contains big air spaces to allow gases to diffuse in and out of the cells
- In the middle of the cross section
Xylem and Phloem
- Transport things like water, mineral ions and food around the plant
- Form a network of vascular bundles, which deliver water and other nutrients to the entire leaf
- Take away glucose produced in photosynthesis
- Help support leaf structure
Meristem tissue
Found at growing tips of shoots and roots and is able to differentiate into lots of different types of plant cell
Phloem purpose
Transport food substances made in the leaves to the rest of the plant for immediate use or storage. The process is called translocation, where many transport can go 2 ways
Phloem is made out of
Long columns of elongated living cells with small pores in the end walls to allow cell sap to flow through
Xylem purpose
Carry water and mineral ions from the roots to the stem and leaves.
Xylem is made out of
Dead cells joined end to end with no end walls between them and a whole down the middle
What is transpiration caused by?
Evaporation and diffusion of water from a plant’s surface (usually happens at leaves) through the stomata
What is transpiration stream?
The movement of water from the roots, through the xylem and out of the leaves
Give some factors that affect transpiration
- Light intensity
- Temperature
- Air flow
- Humidity
How does light intensity affect transpiration?
The brighter the light, the greater the transpiration rate. Stomata begin to close as it gets darker as photosynthesis needs sunlight which keeps in water vapour
How does temperature affect transpiration?
The warmer it is, the faster transpiration happens because particles have more energy which speeds up diffusion
How does air flow affect transpiration?
The better the air flow, the greater the transpiration rate because if the air flow is bad, the water vapour will just surround the plant
How does humidity affect transpiration?
The drier the air around a leaf, the faster transpiration happens. This happens because the concentration is not that much different
How are guard cells shaped?
Kidney shaped which open and close the stomata in a leaf
When does a guard cell open and close a leaf?
- When the plant cell has lots of water, the guard cells fill it and go plump turgid which makes the stomata open so gases can be exchanged for photosynthesis
- When the plant is short of water, guard cells lose water and become flaccid, making the stomata close which helps stop too much water vapour escaping
What type of walls do guard cells have?
Thin outer walls and thickened inner walls
Are guard cells sensitive to light?
Yes
Why is less water lost on the under side of the leaf?
The lower surface is shaded and cooler
