B2 Cell Organisation Flashcards
Define Cell.
Building block of life.
Define Specialised Cell.
A cell adapted to carry out a specific function. The process by which cells become specialise is called differentiation.
What is the job of the systems in large multicellular organisms?
Exchanging and transporting material.
Define Tissue.
A group of similar cells that work together to carry out a particular function.
Define Organ.
A group of tissues that work together to perform a certain function.
Define Organ systems.
A group of organs working together to perform a particular function.
What organs are in the digestive systems (in the order they come).
The digestive system begins in the mouth. It is followed by the salivary gland, pancreas, stomach, liver, small intestine, large intestine,rectum and anus.
What is an enzyme?
An enzyme is a natural catalyst, they are large proteins made up of amino acids.
What is a catalyst?
A catalyst is a substance which increases rate of reaction without being changed or used up during the reaction.
What is the lock and key model?
The lock and key model means that enzymes only ever fit one type of substrate. Enzyme’s active sites are the right size and chemically accurate to fit a specific substrate.
What does the graph of optimum temperature look like?
It gradually increases and then falls suddenly. The highest point is optimum temperature.
What is meant by optimum temperature?
Optimum temperature is the best temperature for enzyme activity and thus increases rate of reaction.
What is meant by optimum pH?
Optimum pH is the best acidity for enzyme activity and thus increases rate of reaction.
What does the graph of optimum pH look like?
It gradually increases and then falls gradually. The highest point is optimum pH.
How do you calculate rate of reaction?
Rate = 100/time
How do you test for starch?
Iodine - Blue-black
You drop a few drops of iodine on the food, if it turns black-blue, it contains starch, otherwise, there is no starch.
How do you test for sugar?
Benedict’s -Orangey red
Add equal quantities of water and Benedict’s solution to the food sample in the test tube, place it in a tub of 95 degree centigrade water bath. If the liquid turns cloudy orange or brick red starch is present.
How do you test for protein?
Biurets - Purple
Place the food sample into a test tube, add water to the tube and stir to mix, add an equal volume of potassium hydroxide solution to the tube and stir, then add two drops of copper sulfate solution and stir for two minutes.
Proteins are detected using Biuret reagent . This turns a mauve or purple colour when mixed with protein.
How do you test for fats?
Ethanol (Sudan III) - Cloudy
Place the food sample into a test tube and add ethanol and an equal volume of distilled water to the tube, cover and shake the tube vigorously. Allow the contents to settle. A milky-whiteemulsion forms if the test substance contains lipids.
What does it mean if an enzyme i denatured?
This is when (due to incorrect pH, temperature) the active site on the enzyme changes becoming a wrong fit.
What enzyme breaks down starch and into what product?
Amylase breaks down starch, it breaks it down, first into maltose and then glucose and other sugars.
Amylase breaks down starch, where is it produced?
Amylase is produced in the salivary glands, pancreas and small intestine.
What enzyme breaks down protein and into what product?
Protease breaks down proteins into amino acids.
Protease breaks down proteins, where is it produced and what is the product of this reaction?
Protese is produces in the stomach (called pepsin), pancreas (called trypsin) and the small intestine (called peptidase).into amino acids.
What enzyme breaks down lipids and into what product?
Lipase breaks down lipids into glycerol and fatty acids.
What is the job of bile?
Bile neutralises acids leaving the stomach and emulsifies fat (breaks fat into smaller pieces with a larger surface area so it digests faster).
What is the job of the salivary glands?
Salivary glands produce salivary amylase which breaks down starch in the mouth.
What is the job of the gullet or oesophagus?
Transporting food for digestion and mechanical breaking down of food through muscular contractions.
What is the job of the mouth?
The mouth is where salivary amylase is released into the mouth to break down protein and where technical digestion of all food occurs through biting.
What is the job of the stomach?
As well as churning food, the stomach is also responsible for breaking down protein using the protease, pepsin. It also produces hydrochloric acid to kill bacteria and to ensure the correct pH for pepsin to work..
What is the job of the liver?
The liver produces bile. Bile neutralises stomach acids and emulsifies fat.
What is the job of the gall bladder?
The gall bladder is where bile is stored and then releases it into the small intestine.
What is the job of the pancreas?
The pancreas produce protease, amylase and lipase enzymes. It releases these into the small intestine.
What is the job of the Large Intestine?
Where excess water from food is absorbed.
What is the job of the Small Intestine?
Produces digestive enzymes and absorbs digested food into the blood stream.
What is the job of the Rectum?
Where faeces is stored before being excreted by the anus.
What is the thorax?
Upper part of your body
Describe which organs air goes through before gas exchange
pathway of air
Nasal cavity/ Mouth Trachea Bronchus Bronchiole Alveoli
What protects the lungs?
Pleural membranes
Ribs
What is the job of intercostal muscles?
To assist in inhalation by moving the ribs upwards and outwards to increase the chest cavity.
What is the job of the diaphragm?
To assist in inhalation by pulling the bottom of the lungs down to increase the chest cavity
How are alveoli specialised to do their jobs?
- Large Surface Area
- Many of them
- Good Blood Supply
- Only 1 cell thick
What occurs in the alveoli?
Gas exchange.
Describe the process of gas exchange during inhalation.
Oxygen enters the alveoli during inhalation,
Blood entering the network of capillaries leading up to the alveoli are deoxygenated,
Oxygen diffuse across the walls of the alveoli and capillary from an area of high concentration to an area of low concentration to be used in respiration.
Describe the process of gas exchange during exhalation.
Blood entering the network of capillaries leading up to the alveoli carry waste products such as carbon dioxide,
There is little or no carbon dioxide in the lungs,
Carbon dioxide diffuse across the walls of the capillaries and alveoli from an area of high concentration to an area of low concentration to be excreted.
What are the four elements of blood?
- Red Blood Cells
- White Blood Cells
- Platelets
- Plasma
What is the function of red blood cells?
Carry oxygen
What allows red blood cells to carry oxygen?
Oxygen connects to haemoglobin to create oxyhemoglobin.
What is the function of white blood cells?
To fight infections
What is the function of platelets?
To create blood clots
What is the function of plasma?
To carry waste products
Why is the circulatory system called a double circulatory system?
It consists of two full circulations
See Figure 3
Starting in as deoxygenated and entering the heart, describe the pathway of blood
Deoxygenated blood enters through the vena cava and into the right atrium
At the first pump a valve opens and allows it into the right ventricle
On the second pump it is forced out of the heart through the pulmonary artery
This then reaches the lungs where it is oxygenated
Oxygenated blood then returns to the heart through the pulmonary vein and into the left atrium
At the first pump a valve opens and allows it into the left ventricle
On the second pump it is forced out of the heart through the aorta, this takes it to the rest of the body
Blood returns to the heart deoxygenated
(See Figure 4)
What causes the heart to pump twice?
There are 4 valves, in the first pump to open and in the second the other two do
Describe the function of valves
They prevent blood travelling backwards in the system
What controls the speed of heart beats?
A pacemaker
Describe how a pacemaker works
It produces a small electric impulse which spreads around the muscle causing it to contract
Describe a pacemaker (physically)
A small group of cells in the wall of the right atrium
Describe a solution for when a patients heartbeats are irregular
Artificial pacemaker