Unit Biology 3

Lungs absorbing food and plants

Dissolved substances move by diffusion Substances are sometimes absorbed against a concentration

gradient This requires the use of more energy from respiration The process is called active transport It enables cells to absorb ions from very dilute solutions

In humanso the surface area of the lungs is increased by the alveolio surface area of small intestine by villi

The lungs are separated from the lower part of the body (abdomen) by the diaphragm

The breathing system allows oxygen from the air to diffuse into the bloodstream and carbon dioxide to diffuse out of the bloodstream into the air

Adaptations for gas exchangeo Lungs have millions of tiny alveoli giving them large surface

area o Alveoli have a moist thin layer of water o Rich supply of bloo vessels o Walls of alveoli = one cell thick diffusion takes place easily

+ efficiently

Small intestine adapted to absorb + digest foodo 3 metres long therefore long length for absorption +

diffusion of substances to take place o Finger like projections -the villi- provide a large surface area

with o an extensive network of capillaries to absorb the products of

digestion by diffusion and active transport (transports absorbed glucose + amino acids into blood system ) (transports fats into lymphatic system)

o Each villus has a branch of the lymphatic system for transporting fats ndash makes it a lot easier

o Micro villi found on villi ndash expand SA further Found in the ileum (end of the small intestine)

In plantso carbon dioxide enters leaf cells by diffusiono most of the water and mineral ions are absorbed by root hair

cells by active transporto Surface area of roots is increased by root hairso surface area of leaves by the flattened shape and internal air

spaces

Plants have stomata to obtain carbon dioxide from the atmosphere Plants lose water vapour from the surface of their leaves This loss of water vapour is called transpiration

Factors affecting transpirationo rapid in hot o dry o windy conditions

Most of the transpiration is through stomata The size of stomata is controlled by guard cells which surround them If plants lose water faster than it is replaced by the roots the stomata can close to prevent wilting

Transporting blood

Substances are transported around the body by the circulation system

o Hearto blood vessels o blood

Blood flows from the heart to the organs through arteries and returns through veins

In the organs blood flows through capillaries Substances needed by cells in the body tissues pass out of the

blood Waste substances produced by the cells pass into the blood through

the walls of the capillaries There are two separate circulation systems (double circulation)

one to the lungs and one to all the other organs of the body

Blood plasma transportso carbon dioxide from the organs to the lungso soluble products of digestion from the small intestine to other

organso urea from the liver to the kidneyso RBCo Platelets o WBC

Red blood cellso transport oxygen from the lungs to the organso are packed with a red pigment called haemoglobin

Haemoglobin combines with oxygen to form oxy-haemoglobin When blood is pumped to tissues + organs splits into oxygen +

haemoglobin and oxygen diffuses out of the capillaries

Exercise and respiration The energy that is released during respiration is used to enable

muscles to contract During exercise a number of changes take place

o Heart rate increaseso Rate and depth of breathing increaseso Arteries supplying the muscles dilateo Glycogen stores in the muscle are used during exercise

These changes increase the blood flow to the muscles and so increase the supply of sugar and oxygen and increase the rate of removal of carbon dioxide

Anaerobic respiration is the incomplete breakdown of glucose - produces lactic acid

Much less energy is released than during aerobic respiration Anaerobic respiration results in an oxygen debt that has to be

repaid in order to oxidise lactic acid to carbon dioxide and water

Microbiology

bacteria are used in yoghurt and cheese manufacture Yeast is used in making bread and alcoholic drinks Yeast is a single-celled organism Yeast can respire without oxygen (anaerobic respiration)

producing carbon dioxide and ethanol (alcohol) This is called fermentation Aerobic respiration provides more energy and is necessary for the

yeast to grow and reproduce

In brewing beer and wine-making carbohydrates are used as an energy source for yeast to respire

For making beero the starch in barley grains is broken down into a sugary

solution by enzymes in a process called malting to form a sugar called maltose

o the sugary solution is extracted then fermentedo Hops are then added to give the beer flavour

In wine-makingo Yeast uses natural sugars in grapes as its energy source

In the production of yoghurt o a starter of bacteria is added to warm milk

o the bacteria ferment the milk sugar (lactose) producing lactic acid

o the lactic acid causes the milk to clot and solidify into yoghurt

Industrial fermenters usually haveo an air supply ndash to provide oxygen for respiration of the

microorganismso a stirrer to keep the microorganisms in suspension and

maintain an even temperatureo a water-cooled jacket to remove heat produced by the

respiring microorganismso instruments to monitor factors such as pH and temperature

The antibiotic penicillin is made in a fermenter The medium contains sugar and other nutrients

The Penicillium only starts to make penicillin after using up most of the nutrients for growth

The fungus Fusarium is used to make mycoprotein a protein-rich food suitable for vegetarians

The fungus is grown on starch in aerobic conditions and the biomass is harvested and purified

Biogas

Fuels can be made from natural products by fermentationBiogas mainly methane can be produced by anaerobic fermentation of a wide range of plant products or waste material containing carbohydrates

On a large scale waste from sugar factories or sewage works can be used

On a small scale biogas generators can be used to supply the energy needs of individual families or farms

Many different microorganisms are involved in the breakdown of materials in biogas production

Ethanol-based fuels can be produced by the anaerobic fermentation of sugar cane juices and from glucose derived from maize starch by the action of carbohydrase The ethanol is distilled from the products of the fermentation and can be used in motor vehicle fuels

People whose kidneys do not function properly die because toxic substancesaccumulate in their blood Their lives can be saved by using dialysis machines orhaving a healthy kidney transplantedCandidates should usetheir skills knowledge and

understanding of how scienceworksto evaluate the advantages and disadvantages of treating kidneyfailure by dialysis or kidney transplantTheir skills knowledge andunderstanding of how scienceworks should be set in thesesubstantive contextsA healthy kidney produces urine byminusfirst filtering the bloodminusreabsorbing all the sugarminusreabsorbing the dissolved ions needed by the bodyminusreabsorbing as much water as the body needsminusreleasing urea excess ions and water as urineHT 10487291048729Sugar and dissolved ions may be actively absorbed against aconcentration gradientPeople who suffer from kidney failure may be treated either byusing a kidney dialysis machine or by having a healthy kidneytransplantedIn a dialysis machine a personrsquos blood flows between partiallypermeable membranes The dialysis fluid contains the sameconcentration of useful substances as the blood This ensures thatglucose and useful mineral ions are not lost Urea passes out fromthe blood into dialysis fluid Treatment by dialysis restores theconcentrations of dissolved substances in the blood to normallevels and has to be carried out at regular intervalsBiology - General Certificate of Secondary Education 2012 examination52 hijA kidney transplant enables a diseased kidney to be replaced witha healthy one from a donor However the donor kidney may berejected by the immune system unless precautions are takenTo prevent rejection of the transplanted kidneyminusa donor kidney with a lsquotissue-typersquo similar to that of therecipient is usedminusthe recipient is treated with drugs that suppress the immunesystem

Plants have stomata to obtain carbon dioxide from the atmosphere Plants lose water vapour from the surface of their leaves This loss of water vapour is called transpiration

Factors affecting transpirationo rapid in hot o dry o windy conditions

Most of the transpiration is through stomata The size of stomata is controlled by guard cells which surround them If plants lose water faster than it is replaced by the roots the stomata can close to prevent wilting

Transporting blood

Substances are transported around the body by the circulation system

o Hearto blood vessels o blood

Blood flows from the heart to the organs through arteries and returns through veins

In the organs blood flows through capillaries Substances needed by cells in the body tissues pass out of the

blood Waste substances produced by the cells pass into the blood through

the walls of the capillaries There are two separate circulation systems (double circulation)

one to the lungs and one to all the other organs of the body

Blood plasma transportso carbon dioxide from the organs to the lungso soluble products of digestion from the small intestine to other

organso urea from the liver to the kidneyso RBCo Platelets o WBC

Red blood cellso transport oxygen from the lungs to the organso are packed with a red pigment called haemoglobin

Haemoglobin combines with oxygen to form oxy-haemoglobin When blood is pumped to tissues + organs splits into oxygen +

haemoglobin and oxygen diffuses out of the capillaries

Exercise and respiration The energy that is released during respiration is used to enable

muscles to contract During exercise a number of changes take place

o Heart rate increaseso Rate and depth of breathing increaseso Arteries supplying the muscles dilateo Glycogen stores in the muscle are used during exercise

These changes increase the blood flow to the muscles and so increase the supply of sugar and oxygen and increase the rate of removal of carbon dioxide

Anaerobic respiration is the incomplete breakdown of glucose - produces lactic acid

Much less energy is released than during aerobic respiration Anaerobic respiration results in an oxygen debt that has to be

repaid in order to oxidise lactic acid to carbon dioxide and water

Microbiology

bacteria are used in yoghurt and cheese manufacture Yeast is used in making bread and alcoholic drinks Yeast is a single-celled organism Yeast can respire without oxygen (anaerobic respiration)

producing carbon dioxide and ethanol (alcohol) This is called fermentation Aerobic respiration provides more energy and is necessary for the

yeast to grow and reproduce

In brewing beer and wine-making carbohydrates are used as an energy source for yeast to respire

For making beero the starch in barley grains is broken down into a sugary

solution by enzymes in a process called malting to form a sugar called maltose

o the sugary solution is extracted then fermentedo Hops are then added to give the beer flavour

In wine-makingo Yeast uses natural sugars in grapes as its energy source

In the production of yoghurt o a starter of bacteria is added to warm milk

o the bacteria ferment the milk sugar (lactose) producing lactic acid

o the lactic acid causes the milk to clot and solidify into yoghurt

Industrial fermenters usually haveo an air supply ndash to provide oxygen for respiration of the

microorganismso a stirrer to keep the microorganisms in suspension and

maintain an even temperatureo a water-cooled jacket to remove heat produced by the

respiring microorganismso instruments to monitor factors such as pH and temperature

The antibiotic penicillin is made in a fermenter The medium contains sugar and other nutrients

The Penicillium only starts to make penicillin after using up most of the nutrients for growth

The fungus Fusarium is used to make mycoprotein a protein-rich food suitable for vegetarians

The fungus is grown on starch in aerobic conditions and the biomass is harvested and purified

Biogas

Fuels can be made from natural products by fermentationBiogas mainly methane can be produced by anaerobic fermentation of a wide range of plant products or waste material containing carbohydrates

On a large scale waste from sugar factories or sewage works can be used

On a small scale biogas generators can be used to supply the energy needs of individual families or farms

Many different microorganisms are involved in the breakdown of materials in biogas production

Ethanol-based fuels can be produced by the anaerobic fermentation of sugar cane juices and from glucose derived from maize starch by the action of carbohydrase The ethanol is distilled from the products of the fermentation and can be used in motor vehicle fuels

People whose kidneys do not function properly die because toxic substancesaccumulate in their blood Their lives can be saved by using dialysis machines orhaving a healthy kidney transplantedCandidates should usetheir skills knowledge and

understanding of how scienceworksto evaluate the advantages and disadvantages of treating kidneyfailure by dialysis or kidney transplantTheir skills knowledge andunderstanding of how scienceworks should be set in thesesubstantive contextsA healthy kidney produces urine byminusfirst filtering the bloodminusreabsorbing all the sugarminusreabsorbing the dissolved ions needed by the bodyminusreabsorbing as much water as the body needsminusreleasing urea excess ions and water as urineHT 10487291048729Sugar and dissolved ions may be actively absorbed against aconcentration gradientPeople who suffer from kidney failure may be treated either byusing a kidney dialysis machine or by having a healthy kidneytransplantedIn a dialysis machine a personrsquos blood flows between partiallypermeable membranes The dialysis fluid contains the sameconcentration of useful substances as the blood This ensures thatglucose and useful mineral ions are not lost Urea passes out fromthe blood into dialysis fluid Treatment by dialysis restores theconcentrations of dissolved substances in the blood to normallevels and has to be carried out at regular intervalsBiology - General Certificate of Secondary Education 2012 examination52 hijA kidney transplant enables a diseased kidney to be replaced witha healthy one from a donor However the donor kidney may berejected by the immune system unless precautions are takenTo prevent rejection of the transplanted kidneyminusa donor kidney with a lsquotissue-typersquo similar to that of therecipient is usedminusthe recipient is treated with drugs that suppress the immunesystem

Exercise and respiration The energy that is released during respiration is used to enable

muscles to contract During exercise a number of changes take place

o Heart rate increaseso Rate and depth of breathing increaseso Arteries supplying the muscles dilateo Glycogen stores in the muscle are used during exercise

These changes increase the blood flow to the muscles and so increase the supply of sugar and oxygen and increase the rate of removal of carbon dioxide

Anaerobic respiration is the incomplete breakdown of glucose - produces lactic acid

Much less energy is released than during aerobic respiration Anaerobic respiration results in an oxygen debt that has to be

repaid in order to oxidise lactic acid to carbon dioxide and water

Microbiology

bacteria are used in yoghurt and cheese manufacture Yeast is used in making bread and alcoholic drinks Yeast is a single-celled organism Yeast can respire without oxygen (anaerobic respiration)

producing carbon dioxide and ethanol (alcohol) This is called fermentation Aerobic respiration provides more energy and is necessary for the

yeast to grow and reproduce

In brewing beer and wine-making carbohydrates are used as an energy source for yeast to respire

For making beero the starch in barley grains is broken down into a sugary

solution by enzymes in a process called malting to form a sugar called maltose

o the sugary solution is extracted then fermentedo Hops are then added to give the beer flavour

In wine-makingo Yeast uses natural sugars in grapes as its energy source

In the production of yoghurt o a starter of bacteria is added to warm milk

o the bacteria ferment the milk sugar (lactose) producing lactic acid

o the lactic acid causes the milk to clot and solidify into yoghurt

Industrial fermenters usually haveo an air supply ndash to provide oxygen for respiration of the

microorganismso a stirrer to keep the microorganisms in suspension and

maintain an even temperatureo a water-cooled jacket to remove heat produced by the

respiring microorganismso instruments to monitor factors such as pH and temperature

The antibiotic penicillin is made in a fermenter The medium contains sugar and other nutrients

The Penicillium only starts to make penicillin after using up most of the nutrients for growth

The fungus Fusarium is used to make mycoprotein a protein-rich food suitable for vegetarians

The fungus is grown on starch in aerobic conditions and the biomass is harvested and purified

Biogas

Fuels can be made from natural products by fermentationBiogas mainly methane can be produced by anaerobic fermentation of a wide range of plant products or waste material containing carbohydrates

On a large scale waste from sugar factories or sewage works can be used

On a small scale biogas generators can be used to supply the energy needs of individual families or farms

Many different microorganisms are involved in the breakdown of materials in biogas production

Ethanol-based fuels can be produced by the anaerobic fermentation of sugar cane juices and from glucose derived from maize starch by the action of carbohydrase The ethanol is distilled from the products of the fermentation and can be used in motor vehicle fuels

People whose kidneys do not function properly die because toxic substancesaccumulate in their blood Their lives can be saved by using dialysis machines orhaving a healthy kidney transplantedCandidates should usetheir skills knowledge and

understanding of how scienceworksto evaluate the advantages and disadvantages of treating kidneyfailure by dialysis or kidney transplantTheir skills knowledge andunderstanding of how scienceworks should be set in thesesubstantive contextsA healthy kidney produces urine byminusfirst filtering the bloodminusreabsorbing all the sugarminusreabsorbing the dissolved ions needed by the bodyminusreabsorbing as much water as the body needsminusreleasing urea excess ions and water as urineHT 10487291048729Sugar and dissolved ions may be actively absorbed against aconcentration gradientPeople who suffer from kidney failure may be treated either byusing a kidney dialysis machine or by having a healthy kidneytransplantedIn a dialysis machine a personrsquos blood flows between partiallypermeable membranes The dialysis fluid contains the sameconcentration of useful substances as the blood This ensures thatglucose and useful mineral ions are not lost Urea passes out fromthe blood into dialysis fluid Treatment by dialysis restores theconcentrations of dissolved substances in the blood to normallevels and has to be carried out at regular intervalsBiology - General Certificate of Secondary Education 2012 examination52 hijA kidney transplant enables a diseased kidney to be replaced witha healthy one from a donor However the donor kidney may berejected by the immune system unless precautions are takenTo prevent rejection of the transplanted kidneyminusa donor kidney with a lsquotissue-typersquo similar to that of therecipient is usedminusthe recipient is treated with drugs that suppress the immunesystem

o the bacteria ferment the milk sugar (lactose) producing lactic acid

o the lactic acid causes the milk to clot and solidify into yoghurt

Industrial fermenters usually haveo an air supply ndash to provide oxygen for respiration of the

microorganismso a stirrer to keep the microorganisms in suspension and

maintain an even temperatureo a water-cooled jacket to remove heat produced by the

respiring microorganismso instruments to monitor factors such as pH and temperature

The antibiotic penicillin is made in a fermenter The medium contains sugar and other nutrients

The Penicillium only starts to make penicillin after using up most of the nutrients for growth

The fungus Fusarium is used to make mycoprotein a protein-rich food suitable for vegetarians

The fungus is grown on starch in aerobic conditions and the biomass is harvested and purified

Biogas

Fuels can be made from natural products by fermentationBiogas mainly methane can be produced by anaerobic fermentation of a wide range of plant products or waste material containing carbohydrates

On a large scale waste from sugar factories or sewage works can be used

On a small scale biogas generators can be used to supply the energy needs of individual families or farms

Many different microorganisms are involved in the breakdown of materials in biogas production

Ethanol-based fuels can be produced by the anaerobic fermentation of sugar cane juices and from glucose derived from maize starch by the action of carbohydrase The ethanol is distilled from the products of the fermentation and can be used in motor vehicle fuels

People whose kidneys do not function properly die because toxic substancesaccumulate in their blood Their lives can be saved by using dialysis machines orhaving a healthy kidney transplantedCandidates should usetheir skills knowledge and

understanding of how scienceworksto evaluate the advantages and disadvantages of treating kidneyfailure by dialysis or kidney transplantTheir skills knowledge andunderstanding of how scienceworks should be set in thesesubstantive contextsA healthy kidney produces urine byminusfirst filtering the bloodminusreabsorbing all the sugarminusreabsorbing the dissolved ions needed by the bodyminusreabsorbing as much water as the body needsminusreleasing urea excess ions and water as urineHT 10487291048729Sugar and dissolved ions may be actively absorbed against aconcentration gradientPeople who suffer from kidney failure may be treated either byusing a kidney dialysis machine or by having a healthy kidneytransplantedIn a dialysis machine a personrsquos blood flows between partiallypermeable membranes The dialysis fluid contains the sameconcentration of useful substances as the blood This ensures thatglucose and useful mineral ions are not lost Urea passes out fromthe blood into dialysis fluid Treatment by dialysis restores theconcentrations of dissolved substances in the blood to normallevels and has to be carried out at regular intervalsBiology - General Certificate of Secondary Education 2012 examination52 hijA kidney transplant enables a diseased kidney to be replaced witha healthy one from a donor However the donor kidney may berejected by the immune system unless precautions are takenTo prevent rejection of the transplanted kidneyminusa donor kidney with a lsquotissue-typersquo similar to that of therecipient is usedminusthe recipient is treated with drugs that suppress the immunesystem

understanding of how scienceworksto evaluate the advantages and disadvantages of treating kidneyfailure by dialysis or kidney transplantTheir skills knowledge andunderstanding of how scienceworks should be set in thesesubstantive contextsA healthy kidney produces urine byminusfirst filtering the bloodminusreabsorbing all the sugarminusreabsorbing the dissolved ions needed by the bodyminusreabsorbing as much water as the body needsminusreleasing urea excess ions and water as urineHT 10487291048729Sugar and dissolved ions may be actively absorbed against aconcentration gradientPeople who suffer from kidney failure may be treated either byusing a kidney dialysis machine or by having a healthy kidneytransplantedIn a dialysis machine a personrsquos blood flows between partiallypermeable membranes The dialysis fluid contains the sameconcentration of useful substances as the blood This ensures thatglucose and useful mineral ions are not lost Urea passes out fromthe blood into dialysis fluid Treatment by dialysis restores theconcentrations of dissolved substances in the blood to normallevels and has to be carried out at regular intervalsBiology - General Certificate of Secondary Education 2012 examination52 hijA kidney transplant enables a diseased kidney to be replaced witha healthy one from a donor However the donor kidney may berejected by the immune system unless precautions are takenTo prevent rejection of the transplanted kidneyminusa donor kidney with a lsquotissue-typersquo similar to that of therecipient is usedminusthe recipient is treated with drugs that suppress the immunesystem