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Transcript of biology
: breaking down food
: soluble substances through wall of small intestine into blood then to the Liver
: faeces are pushed out of the anus
: are proteins and are found in living cells and speed up chemical reactions and are biological catylists
: substances needed in the diet to keep healthy
: the building blocks of life
: food is pushed through the alimentary canal.
: stops food entering the windpipe
vitamins and minerals-assist different functions of the body
carbohydrates-main fuel of the body
sugar-quick burst of energy
fibre-holds poo together
water-80%of the body is water, needed to live
fats-source of energy
proteins-build an rebuild muscle
NUTRIENTS IN OUR DIET
oesophagus-tube from mouth to stomach
gall bladder-stores bile
colon-water is absorbed
stomach-makes strong acid
duodenum-breaks down fluid
bile duct-squirts bile
ileum-absorbs broken down food
FUNCTIONS OF THE BODY
TEST INSTRUCTIONS RESULTS
Iodine test for starch Add iodine to starch Turn blue black
Biuret test for protein Add 2cm of liquid Purple
food then add a few
drops of biuret a and b
Benedicts test for sugar Add 2cm of glucose and Blue, orange, red
2cm of benedicts
Emulsion test for fat 1cm of ethanol and 1cm of White emulsion layer
Enzymes turn larger molecules into smaller ones. This is because smaller molecules can pass through walls of the small intestine into the bloodstream via
Enzymes are proteins which break down larger molecules into smaller ones and are only made in glands, such as the pancreas and salivary glands (amylase).
Examples of enzymes are
protease's, carbohydrase's and lipase's.
break down carbohydrates.
break down protein
break down fats.
starch ---------------> simple sugars
spit is can be used as amylase as it has the same function in the mouth.
if iodine is added to a solution of starch,it turns black if you add amylase, the amylase breaks down the starch to glucose. therefore no starch is present when the solution turns back to brown.
EFFECT OF TEMPERATURE ON ENZYME ACTION
enzymes work best at body temperature.
if it is too hot they are denatured.
if it is too cold the reaction is slower.
are protease enzymes
Protease enzymes break down proteins into
PH of the stomach is 2 (kills bacteria)
Proteases needs a low PH to work as fast as possible
carbohydrates-starch,complex sugars simple sugars
EXAMPLES OF FOOD TYPES
carbohydrates(containing starch)- bread, rice, cereal, wheat, potato, pasta, oats
carbohydrates(sugars)-sweets, biscuits, sugar lumps, fizzy drink, fruit, chocolate
fats- fatty meat, dognuts, butter, cream, cheese, chips,crisps, fried food, KFC, MCDONALDS, red meat
protein- chicken, fish, lentils, meat, cheese, eggs, milks, peanuts, beans, pulses
fibre- vegetables, fruit, bran
VITAMINS AND MINERALS
Vitamin A- night vision
vitamin B- needed for healthy nervous system
vitamin C- needed for healthy skin and gums (scurvy)
vitamin D- healthy bones and teeth (rickets)
vitamin E- needed for healthy skin and healing
iron- needed to make red blood cells (heamaglobin)
calcium- healthy bones and teeth
- process where large globules of fat are broken down into smaller ones and made water soluble.
- break down fats into
fatty acids and glycerol
squirted into duodenum
(produced in liver+stored in gall bladder)- helps
of fat into the bloodstream. Green liquids that contain bile salts. It is alkaline
, meaning there is a larger surface area for the
to act. the bile salts work alot quicker than lipase.
optimum temperature for activity is body temperature.
PH also affects the activity of enzymes. lipases work best in neutral or alkaline PH.
Produced by the liver
stored in the gall bladder until needed
yellow green alkaline liquid
travels through bile duct into duodenum where it neutralises stomach acid and increases the PH o the gut contents because the enzymes work best in an alkaline environment.
bile creates an emulsion of the fat globules which increases the surface area so lipases can work better.
a muscular sack with two sphincters
lies between the oesophagus (gullet) and the duodenum (first part of small intestine)
stomach cells secrete hydrochloric acid which kill bacteria and allow protease enzymes to work.
it grinds the food to break it down and increase the surface area.
water and glucose can be absorbed from the stomach.
the pyloric sphincter opens and gastric contents are squirted into the duodenum.
PH of stomach is very acidic (about 2)
made up of duodenum, jejunum and ileum.
its job is to digest food using enzymes from the pancreas and bile from the gall bladder.
it has a very large surface area created by villi.
villi absorb broken down food into the bloodstream which goes to the liver.
pancreas produces important digestive enzymes:
break down complex carbs(starch) to simple sugars (maltose, fructose, glucose)
break down fat into fatty acids and glycerol
break down protein into amino acids.
it also creates insulin which controls blood sugar levels.
- break down complex
(maltose, fructose, glucose)
- break down
(trypsin/pepsin)- break down
function of enzymes
Villi make up the walls of the small bowel (intestine)
They increase surface area for absorption. occur by osmosis or diffusion.
Made up of lacteal, blood supply, cells, gut.
cell wall is thin to allow diffusion.
rich blood supply to carry nutrients to liver.
Fatty acids and glycerol go to the lacteals.
amino acids and glucose go into the bloodstream
Glucose + oxygen
carbon dioxide+ water + energy
(Complete break down of food)
(Incomplete break down of food)
energy + lactate
Anaerobic respiration is inefficient
Anaerobic respiration keeps our bodies going until we can breathe in more oxygen again.
It provides energy but causes a build up of lactate. This causes a stitch.
Whilst we are performing anaerobic respiration, our bodies are building up a debt of oxygen.
can also be called internal respiration
Respiration is the process which releases the energy from the glucose. It occurs in every living cell (plant or animal), it occurs inside mitochondria.
Aerobic and Anaerobic
Lactate needs to be broken down to
CO2 and H20 when O2 is available again
C6 H6 O6 + 6O2
6CO2 + H2O + ATP
Virus and bacteria
Nutrients-substances needed in the diet to keep us healthy.
Food goes into the mouth. The teeth chew the food. The food is mixed with saliva. When we swallow, the food goes down the food pipe to the stomach. In the stomach the food mixes with the acid and gastric juices, which help to break down the food. The food leaves the stomach and goes into the small intestine into the large intestine. Here water is passed out of the undigested food into the blood. Undigested food is stored in the grectum before it passes out the body via the anus.
Movement- muscles are attached
to the bones to allow movement
Ligaments- attach bones by tough elastic
Tendons- attach muscles to bone
Agnostic pair- two muscles that work a joint by pulling in opposite directions
Ball and socket joint- flexible joint move freely
Bone- Hard substance containing calcium
Bone marrow- makes red blood cells inside bone
Cartilage- covers end of bones for protection
Fixed joint- where bones meet but can't move
Hinge joint- bones can move in two directions
Ligament- hold bones together
Muscle- a tissue made from cells.
Vertebrae- small bones in back
Antibiotics- medicine that kills bacteria not viruses
Immunity- you cannot get a disease you are protected (natural or acquired)
Natural- immunity after infection Acquired- immunity via vaccination
Vaccination- injection of a dead/part microbe to make your immune system used to the disease
Infected- When a microbe gets in your body
Resistant- bacteria that are not affected by antibiotics
Vaccine- parts of weakened microbes to stimulate immune system to make antibodies against infection and remembers it. (immunlogical memory)
Internal Fertilisation=inside body
External fertilisation=outside body
Eggs are produced in small numbers, because of protection by body.
The sperm are kept inside the body. In sexual intercourse.
usually land animals
the eggs are produced in large numbers because they are prone to being eaten by predators.
Sperm are released into water around the eggs and can get eaten by predators or washed away.
often used by fish
Asexual reproduction produces clones e.g. plants, bacteria, fungi
Sexual reproduction makes offspring with different charecteristics. e.g. flowering plants +animals
Our sexual organs produce gametes in the man they are sperm and woman are eggsis
Sperms and eggsis meet inside the female body (fallopian tube) and allow internal fertilisation to occur
Protects developing embryo.
The sperms enter the female via the vagina from the penis.
After puberty sperm are produced in the tubules of the testes in huge quantities (100 million) each day. Then they move into the epididymis where they are stored and mature. If an ejaculation occurs the epididymis contracts forcing the sperm, via the sperm duct (vas deferens), sperm mixes with fluid from seminal vesicles and prostate gland making semen and then passes into the urethra and is ejaculated into the world. (sometimes this will land in a vagina. sometimes the sperms will bang their heads against a sheet of rubber called a condom and so can't reach the vagina or eggsis. sometimes they will have a soft landing into the sheets or a tissue. this usually occurs if the person is a mass-debater)
Eggs or ova are released from the ovary intermittently about every four weeks. This is gathered up by the feathery end(fimbriae) of the oviduct (fallopian tube). If fertilisation is to take place, the egg must be met by the sperm before or just after it reaches the uterus or womb. Sperm ejaculated into the vagina during sexual intercourse needs to negotiate a narrow opening through the cervix and then swim up through the uterus, into one of the oviducts. The female urethra is short and only carries urine. The male urethra carries urine and semen.
Taken in through roots
Taken through holes in leaves
Stored as starch
Protoazoa (single cell) and parasite
mosquitoes and humans
attacks red blood cells
bitten by mosquitoes (insect vector) carrying parasite
uninfected mosquitoes pick up parasites when bite infected human
high fever intense sweating chills violent shivering
breaks down RBC's :. gets stuck in capillaries :. organs die
prevention= kill mosqitoes, mosquito reppellent/net wear, long clothes, remove stagnant water, use anti-malarial medicine
Controlling mosquitoes can stop all of these diseases but also you can use vaccines against yellow fever. Malaria is a protozoa and there are anti-malaria medicine against it.
prevention= kill mosqitoes, mosquito reppellent/net wear, long clothes, remove stagnant water, use anti-malarial medicine
e.g. atheletes foot
e.g. chicken pox
Edward Jenner discovered vaccination by putting cow pox into a young boy :. he caught it . later on he put small pox into the boy and he did not get it. This was because cow pox immunised you against small pox. This was because milk maids didn't catch smallpox but cow pox instead.
DNA the molecule of life
DNA- Deoxyriboneucleic acid- carry the code that control how your cells are made and what they do.
DNA are packaged together to form genes
Gene- part of a chromosome + contains DNA
Chromosome- carry genetic info into the nucleus of cells they are long molecules of tightly coiled DNA. These control inherited characteristic.
Inherited characteristic- characteristic passed on from organisms parents e.g. hair colour, skin colour, eye colour, intelligence
When a male and female gamete join together this is called fertilisation the new cell is called a zygote.
Zygote develops into embryo
The embryo develops into a faetus
Implantation- when an embryo sinks into lining of uterus.
Menstrual cycle- series of events lasting about 28 days in female reproductive system. During cycle ovulation occurs. (day 14) If implantation does not occur the lining of uterus breaks down and is lost as blood through the vagina this is called menstruation (period).
Ovulation- releasing egg from ovary
Pregnant- when a woman has an embryo growing inside her uterus
Zygote- a fertilised egg cell formed by male +female sex cells (gametes)
Foetus- after embryo has grown all organs (about 10 weeks know as foetus.)
Placenta- attached to uterus wall, takes o2 plus food out of mum blood and puts waste material in blood.
Amnion- bag containing amniotic fluid
Amniotic fluid- liquid surrounding growing embryo +protecting it.
Umbilical cord- carries food + between the placenta and growing foetus.
Embryo- from fertilisation to about 8 weeks
foetus- 8 weeks till birth
Ribosomes- site of protein synthesis in a cell.
Adenosine Triphosphate (ATP)- transports chemical energy within cells for metabolism.
All cells share same basic plan.
Mitochondria make ATP for the chemical reactions.
Very few cytoplasm
Allows maximum fat storage space
Very few mitochondria
Can expand by X1000
A lazy cell
Sperm Cell- Long tail, swim towards egg, many mitochondria in tail for energy, large nucleus, acromosome, genetic info
Cone cells- Visual pigment, Mitochondria in middle segment,visual pigment absorbs light, mitochondria make ATP, synapse fires electric impules
Prevents water loss
Thin waxy layer
Allow CO2 into leaf
Found in pairs
Large surface area
Contains: a cell wall, cell membrane, flagellum, cytoplasm, DNA
Sometimes the substances needed by your body have to be moved across a concentration gradient, or psrtially permeable membrane
The only way you can do this is to use the energy prodeuced by respiriration.
Sometimes it is worth using up energy when a source is partially valuable
The energy comes from cellular respiration
The rate of celluar respiration and the rate of active transport are closely linked.
DIGESTION OF STARCH BY AMYLASE
Cells and living things
Cells are the basic unit of life. There are many different types of cells, each one has a different job to do.
Tissue are a collection of similar types of cell. An organ is made up of a group of tissue that work together. The heart is an organ. It is made up of muscle tissue, nerve tissue and connective tissue.
Organ systems are made up from units called organs which all work together.
The human body is a living machine made up of organ systems which all work together to keep up alive.
Cnidarians- Have thin sack like bodies and tentacles
Worms- have small bodies
Anolids- segmented worms
Echniderms- Have spines
Arthrapods- Have lots of legs and segmented bodies.
Cells consist of : cell membrane, ribosomes, cytoplasm, mitochondria and nucleus.
Present in all cells?
Animal cells only
Plant cells only
All cells share the same basic plan
The nucleus controls the cells
Cytoplasm is where the chemical reactions occur
Mitochondria make ATP for the chemical reactions
Movement in chemicals in and out are controlled by the cell membrane
Ribosomes make protein.
Fat cells- can expand up to 1000 times original size
Root hair cell- has extension to increase its surface area
Sperm cell- Has a long tail with muscle like proteins
Leaf cell- Contains chloroplasts
Stem cell- Can divide and change into many different types of cell
Cone cell- Contains a chemical called visual pigment
Specialised cells are adapted to carry out particular functions.
They look very different from generalised cells.
The structure of the cell will give you a clue as to its function.
bacteria and viruses
Diffusion is the spread of particles from an area of high concentration to an area of low concentration.
The greater the difference in concentration, the faster the rate of diffusion.
osmosis is the diffusion water from a high concentration of water molecules ( dilute solution) to low concentration of water molecules(a concentrated solution) through a partially permeable membrane. (semi permeable)
Mass in change of core
change of mass/ original mass X 100
The process in plant cells where the plasm membrane pulls away from the cell wall due to the loss of water through osmosis.
Hypertonic- more solute concentration
E.G. strong sucrose
Hypotonic- less solute concentration
E.G. distilled water
Isotonic- same solute concentration
E.G. isotonic drink
Active transport can move chemicals in the opposite direction to diffusion, but needs ATP and carrier proteins to do so.
Active transport occurs against a diffusion gradient.
Diffusion occurs along or down the diffusion gradient.
and Active Transport
The energy from active transport comes from cellular respiration.
For these processes to occur food molecules are broken down.
Pepsin/Trypsin - protein - amino acids-protease
Amylase-carbohydrate-simple sugars- carbohydrase
Lipase- fats- fatty acids- glycerol
Lungs exchange oxygen and Carbon Dioxide.
At rest a person breathes about 14-16 times per minute. After exercise it could increase to over 60 times per minute
Emphysema is a disease of the lungs. People who smoke cigarettes are more likely to suffer from emphysema,
What is the difference between breathing and respiration?
Breathing- gets the oxygen we
Respiration- A chemical reaction that happens in all living cells. It is the way that energy is released from glucose, for our cells to use, to keep us functioning.
Glucose + Oxygen -----> carbon dioxide + water + energy
C6H12O6 + O2 ----------> CO2 + H2O + ATP
Chest cavity increases
Air pressure un chest cavity is less than outside, so air rushes into lungs to balance pressure.
Chest cavity decreases
Air pressure in chest cavity is greater than outisde, so air is pushed out of the lungs.
Musk turtles have tiny tongues that are covered in bud-like papillae that allow them to respire underwater.
Alveoli are tiny air sacs inside the lungs. There are about 600 million alveoli in the lungs. This gives the lungs a very large surface area of about 80m (squared).This large area allows gases to diffuse easily from the air into and out of the blood.
Aerobic respiration occurs in mitochondria.
Enzymes in mitochondria produce carbon dioxide, water and energy.
Fat cells don't have many mitochondria, however muscle cells do.
Oxygen+ Glucose---> Carbon Dioxide + Water + Energy
The energy released is used:
To make larger molecules from smaller ones.
To contract muscles.
To maintain a steady body temperature.
To build up sugars and other nutrients into amino acids which build up into proteins.
Aerobic respiration takes place continuously in both plants and animals. Most of the reactions in anaerobic respiration take place in the mitochondria.
Energy is released from glucose by a process known as respiration.
During respiration, chemical reactions take place inside the mitochondria in the cells of your body.
When glucose reacts with oxygen energy is released.
Carbon dioxide and water are formed as waste products.
The process is known as aerobic respiration because it uses oxygen from the air.
Cellular respiration- is the process by which glucose is broken down inside living cells to produce energy.
Glucose+ oxygen---> carbon dioxide + water + energy
When there is not enough oxygen available Anaerobic respiration occurs.
Much less energy is produced by this process
Glucose----> lactic acid + energy
Body during exercise
Muscles use alot of energy. they move around and help support your body against gravity. Your heart is made of muscle and pumps blood around your body. The movement of food along your gut depends on muscles to.
Muscle tissue is made up of protein fibres. These contract when they are supplied with energy from respiration. Muscle fibres need alot of energy to contract. They contain many mitochondria to carry out aerobic respiration and supply the energy needed.
Muscle fibres usually occur in big blocks or groups known as muscles, which contract to cause movement. They relax, which allows other muscles to work.
Your muscles also store glucose as the carbohydrate glycogen. Glycogen can be converted rapidly back into glucose to use during exercse. The glucose is used in aerobic respiration to provide the energy to make your muscles contract.
Glucose + Oxygen -------> Carbon Dioxide + Water + Energy
Even when you're not moving about your muscles use up a certain amount of oxygen and glucose. However, when you exercise, many muscles start contracting harder and faster. As a result they need more glucose and oxygen to supply their energy needs. During exercise the muscles also produce increased amounts of carbon dioxide. This needs to be removed for muscles to keep working effectively.
Your heart rate increases and the arteries supplying blood to your muscles dilate (widen). These changes increase the blood flow to your exercising muscles. This in turn increases the supply of oxygen and glucose to the muscles. It also increases the rate that carbon dioxide is removed from the body.
Your breathing rate increases and you breathe more deeply. So you breathe more often and also breathe more often and also bring more air into your lungs each time you breathe in. More oxygen is brought into your body and picked up by your red blood cells. This oxygen is carried to your exercising muscles. It also means that more carbon dioxide can be removed from the blood in the lungs and breathed out.
If muscles work hard for a long time they become fatigued and don't contract efficiently. If they don't get enough oxygen they respire anaerobically.
Anaerobic respiration is respiration without oxygen. Glucose is incompletely broken down to form lactic acid.
The anaerobic breakdown of glucose releases less energy that aerobic respiration.
After exercise, oxygen is still needed to break down the lactic acid which has built up. The amount of oxygen needed is known as oxygen debt. Another name for this is Excess Post -exercise Oxygen Consumption (EPOC)
DHL- Diffusion = high----> low
3 factors that increase diffusion area:
greater surface area
Potato experiment and osmosis
Putting a potato core in water makes the cell swollen and
. Putting the potato core in a strong sugar solution makes the cell limp and
Cells sometimes lose so much water plasmolysis occurs.
In less concentrated solutions, the potato gains water and increases mass.
At high concentrations of sugar, the potato loses water and decreases mass.
Cells and Organisation
In plants and fungi, such as yeast, anaerobic respiration is often called f
. It produces different products.
Glucose ---> ethanol + carbon dioxide +energy
Carry blood away from heart
Carry oxygenated blood
Note: Pulmonary artery carries deoxygenated blood from right ventricle to lungs
Very thin walled
One cell thick
Branch off arterioles
Large surface area
Deliver oxygenated blood to tissues
Pick up carbon dioxide and waste products from tissues
Flow to venules, then veins
Carry Deoxygenated blood from body to heart
Muscle pumps encourage flow back to the heart
Drain into vena cava (inferior and superior) both
drain into right atrium
Note: One exeption Pulmonary vein carries oxygenated blood from the lungs to the left atrium
The heart has two halves:
Double circulation in mammals and birds is very efficient.
Straw coloured solution of chemicals dissolved in water
Made up of :
Red Blood Cells
Reacts with oxygen to form oxyhaemoglobin
Involved in transport of Carbon Dioxide
Have a flexible shape to allow them to move through capilleries
Smaller than white blood cells and many more
Small cell fragments
Help with clotting of blood
Stick to areas of damaged endothelieum (lining of blood vessels)
Made in bone marrow
Produced in bone marrow
Multi loabed nucleus
Can move out of capilleries
to find and kill bacteria
Engulf an destroy bacteria
Single large nucleus
Neutralises bacteria and viruses
Help other cells fight bacteria and viruses
Gives your heart electric shocks to keep you alive.
People with heartbeat problems
Can save lives
Can fail (open heart surgery is needed)
Can set off metal detectors
Giving people a new heart
Giving people with failing hearts life.
Gives you an active life
Have to carry around a box (7KG)
Supports artery and vein structure
Rebuilding/growing arteries and veins
Keep people's blood flow going
You have metal inside you (metal detectors)
Replace the old heart with a new one (animal)
People with failing hearts who need new ones.
You can live a normal life.
Animals are sacrficed