Topic 2 - Organisation Flashcards
What are tissues?
Tissues are groups of similar cells that act together to perform a specific function.
What are organs?
Organs are a group of tissues that work together to perform a specific function.
What is an organ system?
An organ system are groups of organs that work together to perform a specific function.
What is in the digestive system?
- Glands
- Large Intestine
- Stomach
- Liver
- Small intestine
What are the glands and what do they do?
The glands are the pancreas and salivary glands and they produce digestive juices.
What does the large intestine do?
The large intestine absorbs water molecules from the remaining undigested food, producing faeces.
What does the stomach do?
The stomach digests food.
What does the liver do?
The liver produces bile.
What does the small intestine do?
The small intestine digests food and absorbs soluble food molecules.
What is an enzyme?`
An enzyme increases the speed of reactions - they are called biological catalysts.
What is the active site?
The active site is if a reaction is trying to be sped up, the reacting chemical (substrate) must bind to the enzyme’s active site. The active site will only fit specific substrates.
What is the lock and key explanation?
The active site is a lock and the substrate is like a key. There is only one enzyme for every substrate - one key for each lock
What factors affect the rate (speed) of enzyme action?
- Temperature
- pH (measure of acidity)
How does temperature affect the rate (speed) of enzyme action?
Increasing the temperature of a working enzyme increases the reacting activity. Enzymes have an optimum temperature. Once this temperature is reached, the activity decreases. Past this certain temperature, the active site changes shape, and the enzyme is denatured.
What does it mean when an enzyme is denatured?
When an enzyme is denatured, the enzyme loses its catalytic activity.
How does pH affects the rate (speed) of enzyme activity?
Enzymes have an optimum pH. If the pH changes away from the optimum pH, then the enzyme activity decreases. If the pH is too high or too low, then the enzyme is denatured and will not function.
How do you calculate rate of reaction?
Calculating rate of reaction is like calculating the gradient of a line. y^2 - y^1 / x^2 - x^1. Change in mass / Change in time
Where are digestive enzymes made and released?
Digestive enzymes are made by specialised cells in the glands and the lining of the gut. They are then secreted (released) out of the body cells and into the cavity of the digestive system.
What are digestive enzymes used for and how?
They are used to breakdown large food molecules. The digestive enzymes catalyse (speed up) the breakdown of large, insoluble food molecules into smaller, soluble (can be dissolved) molecules that are then small enough to be absorbed into the bloodstream.
What can digestive molecules be used to construct?
Digestive molecules can be used to construct new carbohydrates, proteins and lipids in the body.
What can glucose produced by digestion be used for/
Glucose produced by digestion is used for respiration.
What are the 3 main digestive enzymes?
The three main digestive enzymes are:
- Amylase
- Protease
- Lipase
What does carbohydrase break down into sugars?
Carbohydrases break down carbohydrates into sugars.
What is amylase, where is it produced, what is its purpose and where is its action sites?
Amylase is a type of carbohydrase. It is produced in the small intestine, the pancreas and the salivary glands. It breaks down starch into sugars (maltose mainly). Starch –> Maltose (+ other sugars). The action sites of amylase are the small intestine and the mouth.
What is protease, where is it produced, what is its purpose and where is its action sites?
Protease is a type of digestive enzyme that breaks down proteins into amino acids. It is produced in the small intestine, the pancreas and the stomach. Protein –> amino acids. The action sites of protease is the small intestine and stomach.
What is lipase, where is it produced and what is its purpose?
Lipase is a type of digestive enzyme that breaks down lipase into glycerol and fatty acids. It is produced in the small intestine and the pancreas. Lipid –> Glycerol + Fatty acids.
What is bile?
Bile is an alkaline substance that is stored in the gall bladder after having been produced in the liver.
What is emulsification?
Emulsification is a process where bile breaks up fats into tiny droplets. The droplets have a higher SA than the original fat drop. This increases the rate of the lipase-catalysed reactions that breaks fats down.
Why is bile important for optimal enzyme conditions?
Enzymes in the small intestine operate best in alkaline conditions. Bile neutralises acid from the stomach to stop these enzymes becoming denatured.
What are reagents and how do you test with certain reagents?
Reagents can be used to test for the presence of various food substances. Grind up the food and add distilled water to dissolve some of the food. Finally add the specific reagent and find out!
How do you test for sugars?
- Add Benedict’s reagent and heat for about two minutes
- It will turn any of green, yellow or red if sugar is present.
- The colour depends on the concentration
How do you test for lipids?
- Add Sudan III
- If lipids are present, a red-stained oil layer will float on the water surface
How do you test for starch?
- Add iodine solution
- It will turn blue-black if starch is present
How do you test for proteins?
- Add Biuret solution
- It will turn purple if proteins are present
How do blood move around the body?
Blood moves around the body in three different types of blood vessels.
What are the three different types of blood vessels?
Veins, capillaries and arteries.
What do arteries do?
Arteries transport blood away from the heart to the organs. They carry oxygenated (contains oxygens) blood (apart from the pulmonary artery).
How are arteries’ structure adapted to perform their function?
The walls have elastic fibres, which allows them to stretch and spring back. The walls also have thick layers of muscle. This makes them strong and able to cope with the high pressure at which blood is pumped out by the heart.
What do capillaries do?
First of, arteries branch off into much smaller vessels that are capillaries. Waste products (like CO2) move out the cells and into the blood. Food and oxygen move out of the blood and into the cells. They have thin walls and pass very close to the body cells.
What do veins do?
Veins form when capillaries join up after passing through the body. They transport deoxygenated blood (apart from the pulmonary vein) from the organs back to the heart.
How are veins different to arteries?
Veins have thinner walls than arteries as the blood is at a lower pressure. Veins have a wider cross section than arteries - low pressure hinders blood flow - veins must have a wide cross section through which blood can flow to counteract this. Veins have valves to prevent the backflow of blood.
What does pulmonary mean?
Pulmonary means anything related to the lungs.
What is the pulmonary artery and the pulmonary vein’s job?
The pulmonary vein transports oxygenated blood from the lungs to the heart. The pulmonary artery transports deoxygenated blood from the heart to the lungs.
What is the heart?
The heart is the muscular organ that pumps blood around the body.
What are the four chambers of the heart and what is strange about it?
The 4 chambers are the left and right atria and the left and right ventricles. From a normal viewpoint the right atria and ventricle are on the right side. Vice versa for the left atria and ventricle.
What does the heart contain other than the four chambers?
The heart also contains valves and a pacemaker.
What do valves do?
Valves prevent blood flowing backwards.
What is the pacemaker and where is it in the heart?
The pacemaker controls the pumping heart. The pacemaker is a group of cells in the right atrium.
What happens when a heart beats?
Blood enters the heart via the atria. Once the heart is filled with blood, the atria contract, forcing blood down into the ventricles below. When the ventricles contract, they force the blood to exit the heart.
What is the job of the vena cava?
The vena cava takes in deoxygenated blood from the body into the heart.
What is the job of the aorta?
The aorta takes oxygenated blood from the heart to the body.
What are the coronary arteries?
The coronary arteries supply the heart muscle with oxygenated blood.
What do the veins and arteries of the heart do?
The veins (pulmonary vein and vena cava) take blood in from the body to the heart. The arteries (aorta and pulmonary artery) takes blood from the heart to the body.