Biology - Organisation

How red blood cells are adapted to transport oxygen?

Red blood cells are adapted to carry oxygen because they contain haemoglobin, which binds to oxygen to form oxyhaemoglobin. They have a biconcave shape, giving them a large surface area to volume ratio for rapid diffusion of oxygen. They do not contain a nucleus, leaving more space for haemoglobin.

What are the four components of blood?

Red blood cell, white blood cell, plasma, platelets

What are the two double circulatory systems in humans called?

Pulmonary and systemic

What is the function of the arteries?

The arteries carry blood directly away from the heart

What do the veins do?

The veins carry blood towards the heart

What are the functions of the red blood cells?

The role of red blood cells is to carry oxygen from the lungs to the body’s tissues for cellular respiration

What is the function of white blood cells?

White blood cells defend us against infections and destroy pathogens

What is the function of platelets?

When damage to a blood vessel occurs, the platelets are involved in forming a blood clot to prevent blood loss

What is the function of plasmas?

Plasma transports substances around the body, including dissolved nutrients, waste products and hormones.

How are blood cells adapted to transport oxygen?

Red blood cells contain haemoglobin, which binds to oxygen to form oxyhaemoglobin, and it does not contain a nucleus, creating more space for haemoglobin and they have a biconcave shape which gives them a large surface area to be able to absorb oxygen

Why do red blood cells have a biconcave shape?

The biconcave shape gives the cell a large surface area to volume ratio, allowing rapid diffusion of oxygen into and out of the cell.

What is the effect of increasing temperature on enzyme activity?

increasing the temperature of the enzymatic activity increases the

How do you identify the optimum temperature from a graph?

The highest point on the curve is the optimum temperature of the enzyme.

What is an enzyme?

Enzymes are biological catalysts made from protein that speed up chemical reactions in cells without being used up

How do high temperatures denature enzymes?

At temperatures above the optimum, bonds maintaining the enzyme's shape are disrupted because of the high temperature, and this changes the shape of the active site, so the substrate is no longer complementary to the active site and the enzyme is denatured.

What happens to the active site when an enzyme is denatured?

Denaturation changes the shape of the active site, so the substrate is no longer complementary to the active site and the enzyme can no longer catalyse the reaction

Describe the effect of pH on enzymic activity

Each enzyme has an optimum pH at which it works at its maximum rate. As the pH moves away from the optimum, the rate of reaction decreases. Extreme pH can denature the enzyme, changing the shape of the active site.

How can extreme pH denature an enzyme?

Extreme pH denatures the enzyme, changing the shape of its active site. The substrate can no longer fit the active site, so the enzyme can no longer catalyse the reaction.

What is optimum temperature?

The optimum temperature is the temperature at which an enzyme catalyses a reaction at its maximum rate

How do phagocytes defend the body?

Phagocytes engulfs or consumes pathogens, destroying them

What is the function of antitoxins?

Antitoxins can neutralise the toxins that pathogens produce

What is the function of antibodies?

Antibodies can bind to pathogens and help destroy them

What do the capillaries do?

The capillaries exchange nutrients and oxygen with the tissues

Why is the left ventricle thicker than the right ventricle?

The left ventricle pumps blood around the whole body, so it needs to produce a higher pressure. Therefore, it has a thicker muscular wall.

What is the function of the heart?

To pump blood around the body

What is the function of the right atrium?

It receives the deoxygenated blood

What is the function of the left atrium?

It receives the oxygenated blood

What is the function of the valves?

The valves prevent backflow

What is the function of the septum?

The septum prevents the deoxygenated blood from mixing with the oxygenated blood

What do the coronary arteries do?

The coronary arteries supply the heart muscle with oxygenated blood

What does the pulmonary vein do?

The pulmonary vein carries oxygenated blood from the lungs into the left atrium

What is the function of the right ventricle?

The right ventricle pumps deoxygenated blood to the lungs.

What is the function of the left ventricle?

The left ventricle pumps oxygenated blood around the whole body.

What is the function of the pulmonary artery?

It carries deoxygenated blood from the heart to the lungs.

What is the main advantage of having a double circulatory system?

It allows blood to be pumped to the body at high pressure, so oxygen is delivered to cells quickly.

What is the structure of carbohydrates?

Carbohydrates are made form carbon, hydrogen and oxygen atoms

What does amylase do?

Amylase breaks starch down into simple sugars

What is maltase?

Maltase is an enzyme that breaks down maltose to separate the two glucose molecules

Where is the enzyme amylase produced?

Amylase is produced in the salivary glands, pancreas, small intestine

Where is the enzyme protease produced?

stomach, pancreas, small intestine

Where is the enzyme lipase produced?

pancreas, small intestine

What does protease do?

Breaks down proteins into amino acids

What does lipase do?

breaks down lipids into glycerol and fatty acids

Why are enzymes needed in digestion?

Large food molecules cannot be absorbed so enzymes break them down into small soluble molecules that can be absorbed into the bloodstream

Why is it necessary to break down proteins in the digestive system?

Because the proteins are too large molecules to be absorbed into the bloodstream they are broken down by the enzyme, protease into amino acids, which are much smaller molecules that can then be absorbed into the bloodstream

Why is it necessary to break down carbohydrates in the digestive system?

Carbohydrates such as starch are too large molecules to be absorbed, so they are broken down by amylase into sugar molecules. These are small enough to be absorbed into the bloodstream.

Why is it necessary to break down lipids in the digestive system?

Lipids are too large molecules to be absorbed into the bloodstream. They are broken down by lipase into fatty acids and glycerol. These are smaller molecules that can then be absorbed into the body.

How are villi adapted for absorption?

It has a large surface area which allows more nutrients to be absorbed at once, they are one cell thick so substances are able to diffuse quickly, they contain lots of mitochondria which provide them with energy for active transport of some nutrients and they have a good blood supply which maintains a concentration gradient and allows faster diffusion and the villi contain microvilli which increase the surface area

What is the role of the liver in fat digestion?

The liver produces bile which emulsifies fats/lipids into smaller droplets increasing the surface area and it is alkaline and neutralises hydrochloric acid from the stomach

What do the pancreas do in the digestion of fats?

The pancreas produces the digestive enzyme lipase

Explain how an artery is adapted to its function

Arteries have a thick muscular wall to withstand the high pressure of blood leaving the heart and a narrow lumen to maintain high blood pressure

Explain how a vein is adapted to its function

Veins have a large lumen to accommodate the large volume of blood they have thinner walls because blood is at low pressure and valves that prevent backflow of blood

Explain how capillaries are adapted for exchange

Capillaries have walls one cell thick, giving a short diffusion distance, and very narrow lumen to slow blood flow, allowing time for exchange occur

How is the small intestine adapted for absorption?

The small intestine contains villi, which provide a large surface area for absorption. The villi have a thin surface layer, giving a short diffusion distance and they have a good blood supply, which maintains a concentration gradient.

How are lungs adapted for efficient gas exchange?

The lungs contain many alveoli, giving a large surface area. The alveoli and capillaries have walls one cell thick, giving a short diffusion distance. The lungs are ventilated, bringing in oxygen and removing carbon dioxide, which maintains a concentration gradient. The alveoli have a good blood supply, which maintains a concentration gradient. These adaptations allow rapid diffusion of gases.

What is a risk factor?

A risk factor is an aspect of a person's lifestyle, or a substance in their body or environment, linked to an increased rate of a disease

What is the difference between a communicable and non-communicable diseases?

A communicable disease can be transmitted between individuals but non-communicable diseases cannot be transmitted between individuals

What is health?

Health is a state of both physical and mental wellbeing

What is the effect of smoking on health?

Risk of carodvascular disease and lung cancer

What is the effect of obesity on health?

Heart attacks, diabetes 2 and cardiovascular disease

What is the effect of alcohol?

Liver disease

What are the effects of smoking/alcohol on unborn babies?

Can harm the developing baby

What is the function of a leaf?

The leaf is a plant organ and it is the site of photosynthesis and it requires a lot of carbon dioxide and water in order to make sugars

What is the wall of the heart made of?

Epithelial tissue

What is coronary heart disease?

Coronary heart disease is caused by the build-up of fatty material in the coronary arteries, narrowing them and reducing blood flow to the heart muscle.

What is the function of statins?

Statins are used to reduce blood cholesterol levels

What is an artificial heart used for?

Artificial hearts can keep patients alive while waiting for a heart transplant

What is a biological valve?

A valve made form a biological tissue from a human donor or a pig or cow

What is a mechanical valve?

A man-made valve

Compare biological and mechanical valves

Biological valves are made from biological tissue, whereas mechanical valves are man-made. Both can replace faulty heart valves, but both require surgery

What can be done if a patient has heart failure?

A donor heart, or heart and lungs can be transplanted

What are the advantages and disadvantages of statins?

You have to take it regularly for years and they can cause side effects like kidney failure and headaches but it lowers the risk of coronary heart disease as well as other diseases.

What does a stent do?

A stent is an expandable tube in the artery that ensures blood can keep flowing

What are the advantages and disadvantages of stents?

The surgery is quick and it lasts a long time the surgery has risks like it could induce a heart attack or lead to an infection and there is a risk of the patient developing a blood clot

What happens if a valve develops a leak?

Blood can flow backwards through the valve

What are the adaptations of a leaf for photosynthesis?

Leaves have a large surface area to absorb more light, and they contain palisade mesophyll cells containing many chloroplasts to absorb light the spongy mesophyll cells have air spaces, which allow carbon dioxide to diffuse through the leaf and the stomata allow carbon dioxide to enter

What is the function of the stomata?

The function of the stomata is to control gas exchange and water loss

What is the function of the palisade mesophyll?

It contains many chloroplasts and it is the main site for photosynthesis

What is the function of the waxy cuticle?

It reduces water loss from the leaf

What dos the xylem transport?

Water and mineral ions from the roots to the stems and leaves

What is the function of the spongy mesophyll

Contains air spaces that allow gases to diffuse through the leaf

What do guard cells do?

Guard cells control gas exchange and water loss by controlling the opening and closing of the stomata

What does phloem transport?

Dissolved sugars from the leaves to the rest of the plant for immediate use or storage

What happens when guard cells become turgid?

The stomata opens

What is the disadvantage of a heart transplant?

Risk of rejection: the immune system may not accept it and then try to destroy it.

How are xylem cells adapted?

It consists of hollow tubes strengthened by lignin, adapted for transporting water

How are root hair cells are adapted for water uptake?

Root hair cells have a large surface area which increases the rate of water uptake of osmosis

Where is meristem tissue found?

At the growing tips, roots and shoots, it produces new cells for plant growth

What is transpiration?

Transpiration is the evaporation of water from leaves