2. Transport Systems Flashcards
What are cells?
The building blocks of any living thing.
What are tissues?
Groups of cells with a similar structure and function
What are organs?
Different tissues working together
What are organ systems?
Groups of organs that perform a particular function
What are organisms?
A whole living thing
Why do large organisms need a transport system?
- absorb nutrients and respiratory gases and to remove excretory products
- transport materials between exchange surface and the cell
When is there a greater need for a specialised transport system?
When there is a lower SA/V ratio because the organism is more active
What are adaptations of red blood cells?
They have an unusual shape and are concave to give them an increased surface area
What is haemoglobin?
A large protein molecule folded around four iron atoms
Equation for oxyhemoglobin?
Haemoglobin + Oxygen = Oxyhemoglobin
What happens to haemoglobin in a high concentration of oxygen?
It reacts with the oxygen
What happens to oxyhaemoglobin in a low concentration of oxygen?
The oxyhemoglobin splits to form oxygen and haemoglobin and the oxygen diffuses to where it’s needed
What is plasma?
The clear liquid of blood that remains after red blood cells are removed
What does plasma contain?
Water, salts, antibodies and other proteins
What is plasma for?
It’s a transporting medium for cells and a variety of substances
What does plasma help carry out?
Blood clotting, fighting diseases
What do white blood cells do?
Engulf then digest pathogens
What are pathogens?
Microbes that cause disease
What can white blood cells produce?
Antibodies and antitoxins
What are platelets?
Small fragments of cell which are important in blood clotting
What direction do arteries carry blood?
Away from the heart
What direction do veins carry blood?
Towards the heart
Which has a pulse : arteries or veins?
Arteries
What do valves do?
Prevent the back flow of blood as it moves from the body to the heart
What are capillaries?
Blood vessels that form a network between arteries and veins
What artery takes blood to the rest of the body?
Aorta
What vein takes blood from the body to the heart?
Vena cava
What blood vessel takes oxygenated blood towards the heart?
Pulmonary vein
What blood vessel takes deoxygenated blood towards the lungs?
Pulmonary artery
What blood vessel takes blood into the kidney?
Renal artery
Why are capillaries narrow?
- nutrients can reach cells of organs
* blood flow is slowed down and blood pressure is lowered
What is the job of the circulatory system?
To transport blood containing substances such as oxygen around the body
What do coronary arteries supply the heart with?
Oxygen and glucose for respiration
Why is the cardiac muscle of the left ventricle thicker than the right?
It needs to create pressure to pump the blood around the body whereas the left only has to take it to the lungs
What are artificial pacemakers?
Electrical devices that are used to correct irregularities in heart rate
Why are the alveoli good for gas exchange?
- very thin walls make diffusion easy
- moist surface makes diffusion easy as gases dissolve
- spherical shape gives relitavely large surface area for diffusion
What does the breathing system do?
Takes air in and out of the body
What pH is oxygen?
neutral , 7
What pH is CO2?
Acidic,
What are the muscles between the ribs called?
Intercostal muscles
What happens to the pressure as the volume inside the chest increases?
It decreases
What is a stent?
A metal mesh that is placed in the artery
How does a stent open up a blood vessel?
A tiny balloon is inflated to open up the blood vessel and the stent
Advantages/ disadvantages of mechanical valves?
They last for a long time but you have to take medicine
Advantages/ disadvantages of biological valves?
They work well and the patient doesn’t need medicine but they only last for about 15 years
What is coronary heart disease?
Fatty deposits in the walls of the coronary arteries reducing the supply of oxygen to heart muscle
What enzyme does the mouth contain?
Salivary amylase
What does the liver do?
Makes bike
What does the gall bladder do?
Stores bile
What does bile contain?
Bile salts and alkali
What does the stomach squirt on food?
Hydrochloric acid
What enzyme does the stomach produce?
Gastric protease (pepsin)
What enzymes does the pancreas produce?
Pancreatic protease (trypsin)
Pancreatic amylase
Pancreatic lipase
What does the pancreas produce as well as enzymes?
Alkali
What enzymes does the small intestine produce?
Lipase, protease and carbohydrases
What are the two types of carbohydrase that the small intestine produces?
Amylase and Maltese
What do protease enzymes do?
Digest proteins to amino acids
What do lipase enzymes do?
Digests fats or lipids to fatty acids and glycerol
What do amylase enzymes do?
Digests starch to sugars
Where is bile released?
On the food in the small intestine
What does bile do?
Emulsifies lipids from large fat droplets with a small surface area
What does bile NOT contain?
Enzymes
Why does bile emulsify fats?
So that they have larger surface areas so they can be digested quickly and efficiently by lipase enzymes
Why does bile contain alkali?
To provide optimum pH for the action of enzymes
What is absorbed into the blood through the walls of the small intestine?
Small, soluble products of digestion (sugars and amino acids)
What are the small intestines adaptations for absorption?
Villi
Good things about villi?
- they have a rich blood supply for a steep concentration gradient and quicker diffusion
- large surface area
- thin wall so there is a short distance for diffusion to take place
- they have microvilli
What process absorbs nutrients into the blood through the wall of the small intestine?
Active transport
What are enzymes?
Biological catalysts that change the rate of reactions
What are enzymes made up of?
Long chains of amino acids
What is the active site?
The chains of amino acids folded to make shapes which allows other molecules to fit into the enzymes
What is the activation energy?
The minimum amount of energy particles must have to react
What do enzymes do in terms of activation energy?
Lower the activation energy
Are catalysts used up in a reaction?
No, you can use them over and over again
How do catalysts work?
By bringing reacting particles together and lowering the activation energy needed
What is the substrate?
The reactant of a reaction
What is it called when the enzyme and substrate bind together?
The substrate-enzyme complex
How does temperature effect enzymes?
If temperatures are over about 40 degrees the protein structure is affected and the active site shape changed
What is it called when enzymes don’t work anymore?
They have denatured
What temperatures do most enzymes work best in?
20 to 40 degrees
What two factors and affect enzyme action?
pH and temperature
What happens if an enzyme is in the wrong pH ?
Forced and changes the shape of the molecule
What happens to the rate of a reaction as the temperature increases?
It increases
What is the optimum pH for pepsin?
about pH 1.5
What is the optimum pH for trypsin?
about pH 8
Where is pepsin found?
In the stomach along with HCL
Where is pancreatic amylase found?
In the small intestine along with alkaline bile
What would be impossible without enzymes?
Respiration, photosynthesis and protein synthesis
What does amylase in saliva break down starch into?
Simple sugars
What is phenolphthalein?
It is an indicator which turns from colourless (alkali conditions) to pink (acidic conditions)
What are lipase enzymes produced by?
The pancreas and the small intestine
What pH is food leaving the stomach?
Acidic
What pH do lipase and other enzymes in the small intestine work best at?
Alkaline conditions
Where in the digestive system is water reabsorbed?
The large intestine
What is the order of processes that happen in the digestive system?
Ingestion, digestion, egestion
Where is bile produced?
The liver
Which enzymes are involved in digesting starch to glucose?
Amylase and Maltese
Which enzymes are produced by the stomach?
Proteases only
Where is maltase produced?
In the small intestine
Which acid is produced by the stomach?
HCL
What are the finger like projections in the small intestine called?
Villi
What is the name of the process by which absorbed food becomes a part of the body?
Assimilation
What is glucose produced by amylase used for?
Cells of the body during respiration
What are fatty acids and glycerol used for?
As a source of energy or to build cell membranes, make hormones or as fat stores
What is immobilising an enzyme?
When enzymes are fixed to small beads
Why do enzymes get immobilised?
Because usually after a reaction the enzyme and product are mixed up together so enzymes aren’t reusable this way
What are enzymes also used for?
- Production of sugar syrups
- Detergents
- To bring about reactions in normal pressures and temperatures
What are proteases used for in industry?
To pre digest protein in some baby foods
What are carbohydrases used for in industry?
To convert starch into sugar syrup
What are isomerase used for in industry?
To convert glucose syrup into fructose syrup
Which is more sweet; fructose or glucose?
Fructose
What do stomata do?
Allow plants to obtain carbon dioxide from the atmosphere
How does carbon dioxide enter a leaf?
By diffusion
What increase the surface area for diffusion on a leaf?
A flat thin shape and internal air spaces
What are stomata?
Small openings on the leaf surface
What are the opening and closing of stomata controlled by?
Guard cells
How are plant roots adapted for absorption?
They are thin narrow tubes and have cells near growing tips that are root hair cells which increase surface area for the uptake of substances from the soil. They also have short pathways needed for movement of water
What do membranes of root hair cells have? What does this do?
Microvilli which increase surface area
How are plants adapted to take in mineral ions using active transport?
They have plenty of mitochondria to supply the energy needed for active transport
What is transpiration?
The loss of water from a leaf surface
When is transpiration more rapid?
When it is hot, dry, windy or light
Why does both the rate of photosynthesis and transpiration increase in the same conditions?
Increased rates of photosynthesis mean more stomata are opened to let in CO2, so more water is lost through open stomata.
Where are more stomata found on leaves? Why?
The lower surface because this protects them from direct light and energy from the sun.
What is wilting?
When a plant begins to lose water faster than replaced by roots, the leaves collapse and hang down which prevents more water loss
What is a potometer?
A device which can be used to show how the uptake of water by a plant changes with different conditions
What are the factors of transpiration?
- temperature
- humidity
- wind
- light intensity
How does temperature affect transpiration?
It increases it as higher temperature increases kinetic energy of molecules and makes diffusion, osmosis and evaporation happen faster
How does humidity affect transpiration?
It decreases it as when air is humid there is more water vapour in it and humid air is less able to accept more water molecules by evaporation.
How does wind affect transpiration?
It increases transpiration as wind blows water vapour away from the stoma, keeping the concentration gradient high
How does light intensity affect transpiration?
It increases it as light causes stomata to open and wider stomata allow faster diffusion for water vapour out of the leaf
How do plants decrease rate of water loss by transpiration?
- reduced number of stomata
- thick waxy cuticle that stops evaporation and is impermeable to water
- leaves rolled or hairy and stomata sunk in pits
How does a leaf being rolled or stomata being sunk in pits decreased water lost in transpiration?
Traps moist air which increases humidity and reduces diffusion of water vapour
Where is epidermal tissue found?
The top and bottom of leaf and the outside of the stem and roots
What is the function of epidermal tissue?
It is protective; it stops bacteria and fungi from getting in
What are the adaptations of epidermal tissue?
- Cells fit together tightly
- They are clear and colourless so light can pass through to chloroplasts
- Produces a waxy cuticle
Where is palisade mesophyll found?
In the middle of a leaf
What is the function of palisade mesophyll?
Photosynthesis
What are the adaptations of palisade mesophyll?
They have chloroplasts; in fact palisades have the most
Where is spongy mesophyll found?
In the middle of the leaf
What is the function of spongy mesophyll?
Photosynthesis
What are the adaptations of spongy mesophyll?
They have chloroplasts and spaces in between them so gases can circulate (CO2)
Where are xylem found?
Throughout the plant (roots to the rest of the plant)
What is the function of the xylem?
To transport water and mineral salts
What are the adaptations of xylem?
They have lignin in then which means they are hollow tubes
What does lignin do?
It kills cells
Where is the phloem found?
Throughout the plant
What is the function of the phloem?
To transport food in the form of sugars (usually sucrose)
What are the adaptations of phloem?
There are holes in the end walls so that the contents can go up and down
Where is the meristem tissue found?
The tips of roots and shoots
What is the function of meristem tissue?
Mitosis
What are the adaptations of meristem tissue?
The cells divide constantly by mitosis
What is translocation?
The movement of food molecules through the phloem
How are sugars used?
- respiration - release energy
- meristems - where cells are dividing by mitosis for growth
- make cellulose in cell walls
- stored as starch in stems / roots
- moved from storage regions to cells that need them
What is the phloem composed of?
Tubes of elongated cells, cell sap can move from one cell to the next through pores on end walls
How do guard cells control stomata?
They take up water by osmosis and become turgid. Inner walls are rigid so are pulled apart, opening the pore.
In darkness water moves out by osmosis and cell is flaccid and closes pore
What factor do guard cells rely on to change the rate of transpiration?
Light intensity
What tissues are found in the stomach?
- smooth muscle tissue
- glandular tissue
- nervous tissue
- blood
- columnar epithelium - lines stomach
What is the pulmonary artery?
Carries deoxygenated blood from right ventricle to lungs
What is the pulmonary vein?
Receives oxygenated blood from lungs and into left atrium
What is one of the few veins that carries oxygenated blood?
Pulmonary vein
When do faulty heart valves occur?
When valves don’t open/close properly so restrict blood flow or blood leaks backwards
What is the epiglottis?
The flap at the back of the throat
Advantages of stents against bypass surgery?
Stents don’t need a general anaesthetic or a donor or tissue match and its cheap
Disadvantages of stents against bypass surgery?
Blood clotting can occur, expensive and stents don’t work for bad blockages
What do proteases do?
Digest proteins to amino acids
What do lipase do?
Digest fats or lipids to fatty acids ang glycerol
What do amylase do?
Digests starch to sugars
Where is bile produced?
The liver
Where is bile stored?
The gall bladder
Why does bile emulsify fats?
So they have a large surface area and can be digested quickly by lipase
What type of substances are absorbed through the walls of the small intestine?
Small soluble products of digestion
Sugars and amino acids
When is a reaction more likely to happen in terms of enzymes?
- when particles are more likely to bump into each other
- increased energy of their collisions
- activation energy needed is reduced
