Biology What is a carbohydrate?

What are monosaccharides and disaccharides? Give

examples of each.

What are the tests for glucose and starch?

What is a polysaccharide? And what are the 3 main

types?What is a protein?

What are the two types of protein?

What is a lipid?

A substance made up of carbon, hydrogen and

oxygen. It is used as an energy source by the body.

When you add iodine to a starch, it goes from red to

blue/black. Benedict’s reagent, when added to glucose, goes

from blue to orange.

A protein is made up of carbon, hydrogen, oxygen, nitrogen and

sulphur. It is composed of 20 different amino acids made, 12 from liver, 8 (essential) amino acids are obtained from food.

Each gene is a genetic code for the cells to make a protein, and the number and order of amino

acids make the protein.

A lipid is made up of carbon, hydrogen and oxygen. They are

made up of 3 fatty acids which are different chain lengths attached to

glycerol.

• Monosaccharide: One ring sugars, e.g. glucose &

fructose.• Disaccharide: Two ring

sugars, e.g. maltose (glucose x2), lactose

(glucose & galactose) & sucrose (glucose &

fructose).

• Polysaccharide: Many ring sugars.• Starch: Plants convert excess

glucose to starch. Found in rice, cereals, potatoes.

• Cellulose: Makes up the cell wall of plants. We can’t digest it, due to no cellulose enzyme.

• Glycogen: Excess glucose is converted to glycogen as a reserve. Stored in liver and muscle.

• Structured protein: Used for growth and repair. E.g. Keratin (hair and nails), actin and myosin (muscle), collagen (tendon, bones). All insoluble.

• Globular proteins: Soluble proteins which serve different functions. Enzymes, hormones, antibodies, haemoglobin.

What are all the uses of lipids?

What are the two types of fats and their properties?

What are vitamins A, C and D, and what do they do?

What happens if you don’t have enough of vitamins A,

B and C.

What is the formula used for calculating the energy

released when food is burnt?

What are Iron, Calcium, Fibre and water made of, what do they do and how

you get them?

Describe the, “burning the wotsit” experiment.

Define Digestion

• Saturated fats: Of animal origin (e.g. butter & lard). They are

solid at room temperature and have the maximum amount of

hydrogen. • Unsaturated fats: E.g. olive oil,

rapeseed oil, sunflower oil. They are oils at room temperature because they have double

bonds.

Vitamin A: Lack of causes nights blindness, found in fish liver oils

and carotene (carrots).Vitamin C: Lack of causes scurvy. Cells peel apart and wounds don’t

heal. Found in oranges, blackcurrants, other fruits.

Vitamin D: Lack of causes rickets where bones are weak. Found in fish liver oils, but also milk and dairy food. Also produced in the

skin via UV.Iron: Needed to make haemoglobin which carries oxygen in red blood cells. Lack of

causes anaemia (causes extreme llethargy). From red meat and vegetables.Calcium: Needed for healthy bones. Found

in dairy products.Fibre: Roughage, undigested plant

material. Adds bulk to faeces, increases peristalsis, prevents constipation and

bowel cancer.Water: Coolant in the eye, detoxifier,

lubrication, hydration, etc. 3 days without you die.

Making large insoluble food molecules soluble so they can be

absorbed into blood.

• Used for energy.• Storage (can store twice as much

energy gram for gram than carbs).• Insulation.• Protecting vital organs.• Used in cell membranes

(phospholipids and cholesterol).• Used to make steroid hormones (e.g.

testosterone & oestrogen).• Fat is stored in adipose tissue, made

up of glycerol and fatty acids, called triglyceride.

• Vitamin A: Retinol – Makes Rhodopsin, which is used by

rods in your eyes to see in dim light.

• Vitamin C: Ascorbic acid – Is needed to make connective tissue binding cells together.

• Vitamin D: Calciferol – Needed to absorb calcium of the gut.

Energy released in Joules = mass of water (g) x temperature of water (ºC) x4.2J (heat capacity of water, no. of

joules in a calorie, and joules needed to raise 1g of water by 1ºC)

Fill a boiling tube with 10cm cubed of water. Support in it a clamp, then

measure the temperature of the water. Weigh a wotsit and position it on a needle on a cork under the water. Burn the wotsit, stir water

and take final temperature. The rise in temperature, when plugged into the formula gives you the heat. It is

best in a closed system with

What does the mouth do? What does the stomach do?

What does the small intestine do?

What are the final products of digestion which occur

where?

What are villi?How are villi adapted to

digestion?

What does the large intestine do?

What do the pancreas and liver do?

• Muscular bag which churns food.• The glandular lining secretes HCl

to kill bacteria.• Pepsin enzyme speeds up protein breakdown and mucus

protects lining.

In the small intestine:Protease: Proteins to amino acids.

Lipase: Fats to glycerol + fatty acids.

Maltase: Maltose to 2x glucose.Sucrase: Sucrose to glucose +

fructose.Lactase: Lactose to glucose +

galactose.

• They have a large surface area.• They have columnar epithelial cells with

microvilli for further surface area.• Capillary network inside absorbs food

molecules.• Lacteal inside takes up fatty acids +

glycerol.• There are lots of them, tightly packed.

Liver: • Makes and secretes bile into gut via

bile duct. The bile is stored in the gallbladder, and is alkaline to

neutralise stomach acid. It contains bile salts, which emulsify fats too.

Breaks them down to increase surface area.

• Pancreas: Produces pancreatic juice which is alkaline and neutralises

stomach acid in small intestine. Also secretes amylase, lipase and

protease.

• Food ingested to be chewed to create a larger surface area (mechanical

digestion).• Saliva lubricates food with mucus, and

amylase breaks down starch to maltose.

• Food is swallowed, forced down oesophagus by peristalsis. It becomes

a bolus and moves into stomach.

• 7m long, made up of duodenum, jejunum and ileum.

• Chemical digestion takes place here and the absorption of food

molecules.• Various enzymes secreted from

gland wall.

Villi are finger-like projections in the wall of the small intestines, aimed

at increasing surface area.

• 1.5m long, made of colon, rectum and anus.

• Faeces stored in rectum, ingested from the anus.

• Faeces is composed of fibre, bacteria, dead gut cells, bile salt

and pigments and water.

What are enzymes?What is the effect of

temperature on enzymes?

What is the effect of PH on enzymes?

What is respiration?

What is the formula of aerobic respiration?

Describe a test to show organisms produce CO2.

What is anaerobic respiration and the

formula?

What is the formula for fermentation?

As temperature increases, the molecules move around faster and

there are more collisions, which causes the enzyme to react quickly, but past the optimum temperature,

the structure denatures.

Respiration is when glucose is oxidised in cells very gradually by a

series of reactions controlled by enzymes, to produce energy.

Have two test tubes with water. Have an insect

placed on a gauze in one of them. As the insect

respires, the water should become carbonic acid, and you can use an indicator to

test for it.

Anaerobic respiration is when respiration occurs without

oxygen, so less energy released. It occurs during server physical exertion is undertaken, it causes an

oxygen debt, only be used for a short time and releases lactic

acid. The formula is C6H1206→Lactic Acid+Energy

Enzymes are biological catalysts made up of protein that speeds up a reaction and remain unchanged. Each enzyme has a

substrate, which binds (via the lock-and-key method) to the active site of an

enzyme, then catalyses.

Enzymes work within an optimum PH. Too low, it doesn’t work. Too

high, and it denatures.

C6H1206+6O2→6CO2+H2O+Energy

This is fermentation, used in baking and brewing.

C6H1206→Ethanol+CO2+Energy

What happens when you inhale?

What happens when you exhale?

What is the route taken for breathing?

How are your lungs adapted for gaseous exchange?

What are the effects of smoking on respiration?

What are pleural membranes?.

What is the effect of exercise on breathing?

How does gaseous exchange occur in your

lung?

• The diaphragm relaxes, and raises.

• Intercostal muscles relaxes, moving the ribs inwards and

downwards. The elastic recoil of the lungs moves it back to its

original position.• The above decreases pressure,

so air rushes outwards.

• Millions of alveoli give a large surface area.

• Alveoli and capillary wall are each only one cell thick, so there

is a high diffusion gradient.• The steep gradient is maintained

by rapid blood flow in capillaries and ventilation.

Pleural membranes surround each lung, and pleural fluid lies in the cavity outside the lung, which lubricates the lung and

stop it rubbing on the ribs.

Gaseous exchange occurs between the alveolus and red blood cells, in the

capillaries which contain haemoglobin. Oxygen diffuses from alveoli into

haemoglobin to become oxyhaemoglobin, while carbon dioxide is diffused from

capillaries into the alveoli.

• The diaphragm contracts and lowers.• Intercostal muscles contract and raise

the ribs upwards and outwards.• The above increases the volume of the

lungs, which decreases the pressure, so air rushes in.

Nose→trachea→bronchi →bronchioles →alveoli →blood

• The tar can paralyse the cilia in the lining of your trachea, so when goblet cells

secrete mucus to trap dirt, rather than be pushed up by cilia, bacteria and particles are trapped and swallowed, sometimes into the lung to give you bronchitis and

the smoker’s cough.• Alveoli walls break down, so there is less

surface area for gaseous exchange. Lungs lose their elastic recoil, so you breathe less and have to make yourself breathe

out. Patients require pure oxygen.• The carcinogens in tobacco can also

cause cancer, and there are many.

When you exercise very quickly, i.e. sprinting, your body builds up an oxygen

debt due to anaerobic respiration, so afterwards, you breathe deeply and

heavily, so your heart pumps quickly, and your breathing rate goes up. With other exercise, your breathing rate goes up as

your body requires more and more oxygen so it can pump red blood cells

around your body, as there is increased demand.

Explain what blood made from.

What are the properties of plasma, and what does it

contain?

What are the properties of erythrocytes and what do

they contain?What do platelets do?

What do white blood cells, and what are the three

types?

What are the functions of T-Lymphocytes

What are the functions of B-Lymphocytes?

Describe the vaccination process and what happens

when you are infected.

Plasma: Fluid part of the blood, makes up 55% of blood. Contains:• Lipids, fatty acids, cholesterol

• Antibodies, enzymes• Urea

• Mineral ions, electrolytes• Gases (e.g. carbon dioxide)

• Platelets are involved in the clotting process. When a wound opens, they bind together to fill

the wound, to stop foreign objects coming in and prevents

blood loss.

• Killer T lymphoctyes destroys infected cells.

• Helper T-cells co-ordinate the immune response.

When an infection takes place, macrophages go forward and

attack, and natural T killer cells and neutrophils do the same. As well as killer T-cells. Dendritic cells create a

marker by taking samples, which Helper T-cells take, and travel to find the B-cell, which contains the correct antibody fort he pathogen. All together, they kill the pathogen.

• Plasma• Red blood cells (erythrocytes)

• White blood cells• Platelets

Red blood cells: • Biconcave discs for high surface

area-to-volume ratio.• 1/3

haemoglobin/oxyhaemoglobin• Made in bone marrow, broken

down in spleen and liver after 120 days.

• Able to squeeze through capillaries, 1 cell thick

White blood cells are cells which defend the body against pathogens, and are used. The three types are:• Phagocytes: Cells which engulf

and digests pathogens.• Lymphocytes: T and B types

which play key roles in immune system.

• Granulocytes (neutrophils): Types of phagocytes with

granules.

• They produce proteins called antibodies which destroy

pathogens. Each lymphocyte produces 1 type of antibody for its pathogen, on its antigen, the specific molecule on the surface

of its pathogen• Memory B cells are created afterwards which stay for years

and help prevent future invasions.

Describe the heartWhat is the route the heart

takes to pump blood?

What are the three valves, where are they and what do

they do?

What are the differences in purpose between arteries,

veins and capillaries?

What are the differences in structure between arteries,

veins and capillaries?

What is the effect of smoking on the circulatory

system?

What is the effect of exercise on heart rate and

why?

What is the general plan of the circulation system?

Blood from body/head via vena cava→right atrium → tricuspid valve → semilunar valves →pulmonary artery → lungs →blood from lungs from pulmonary veins →left atrium

→mitral/bicuspid valve →left ventricle →semilunar valves →aorta →to body and

head →vena cava

• Arteries: Carries blood from heart to organs.

• Veins: Carries blood from body towards the heart.

• Capillaries: Carries blood through organs, bringing blood

to every cell.

• Nicotine makes red blood cells and platelets sticky, which increases blood

pressure, which damages blood vessels.• Atherosclerosis: Build up of cholesterol

in the wall of the endothelium (cell lining). Increases pressure which when

burst, results in the clotting (thrombosis) of a blood vessel, which

leads to a heart attack.

• The pulmonary circuit carries blood to the lungs to be oxygenated and then

back to the heart. In the lungs, carbon dioxide is removed from the blood, and oxygen taken up by the haemoglobin in

the red blood cells.• The systemic circuit carries blood around the body to deliver the oxygen

and returns de-oxygenated blood to the heart. Blood also carries nutrients and

waste.

Made of cardiac muscle (myogenic muscle), it is 2 pumps that beat at once.

The right side receives deoxygenated blood and pumps it to the lungs, and the left side pumps oxygenated blood to the body. The two sides are separated by the septum. It has 4 chambers, two atria and

two ventricles.

• Bicuspid/Mitral valve: Prevents backflow into the left atria when

left ventricle closes.• Tricuspid valve: Prevents

backflow into the right atria when right ventricle closes.

• Semilunar valves: Prevents backflow into ventricles, located in aorta and pulmonary artery.

• Arteries: Thick wall of muscle and elastic tissue, small lumen

(cavity). Very, very high pressure.

• Veins: Thin wall of muscle and elastic tissue, large lumen. Much

less pressure.• Capillaries: One cell thick for

diffusion of gases, cells near capillary and contains various

gases.

Exercise causes muscles to increase the rate of respiration to provide energy. This

means it requires more oxygen and glucose, and therefore produces more

carbon dioxide. The brain sends a message to the natural pacemaker (SA node) of the heart to increase the heart

rate. Adrenaline is released from the adrenal gland and does the same thing to

the heart.

What are the levels of organisation from

organelles to systems?

What are the: Cell membrane, cytoplasm,

nucleus, cell wall, chloroplast and vacuole and their functions? Which ones are used in plant cells and

which in animal cells?

What are: Diffusion, osmosis and active

transport? Give 3 examples of each.

What happens to a plant cell in a solution which has a lower water potential and a higher water potential? And what happens to red blood cells in low water

potential?

Describe an experiment to show the effect of osmosis

on potato chips.

Describe an experiment to show osmosis in action in a

u-tube.

Name 4 factors which affect the rate of movement of

substances.

Why can a unicellular organism rely on diffusion for movement, but not a multicellular organism?

Cell Membrane: Surrounds and protects cell.

Cytoplasm: Where chemical reactions occur.

Nucleus: Contains DNACell wall: Permeable but rigid

and made of cellulose. Chloroplast: Contains

chlorophyll which photosynthesises.

Vacuole: Contains water and minerals, and it keeps the cell

turgid.*Plant Only In Bold• In a solution with higher water

potential, water enters the plant via osmosis and it enters the vacuole, filling it and making the plant cell turgid as the cytoplasm pushes

against the wall.• Placed in a solution with a lower water potential, the water leaves the

vacuole as the cell shrinks and becomes flaccid.

• A red blood cell when it loses water loses its shape and becomes

crenated.

• Have a u-tube with a semi-permeable membrane in the

middle, and one side a solution with higher water potential, and one of the

sides should have more water put in. Osmosis will level it

out.

A unicellular organism, being so small has a very high surface area-to-volume ratio

and therefore is optimal for diffusion, whereas a multi-cellular organism having

such a low surface area and being so inefficient at diffusion would benefit from

carrying around molecules differently.

Organelles (Microscopic structures in cells having a particular function, e.g. nucleus, mitochondria) → Cells → Tissues → Organs

→ Systems

• Diffusion: The movement of molecules of an area of a high concentration to a low

concentration. E.g. Tea, perfume, alveoli.• Osmosis: The movement of liquids with a

high water potential to a low water potential through a semi-permeable membrane. E.g.

plant roots, kidney, capillaries.• Active transport: The movement of

molecules from an area of low concentration to a high concentration which

requires energy. E.g. root cells absorbing minerals from soil, glucose and amino acids by epithelial cells in gut and glucose from

glomerular filtrate by tubules in your kidney.

Set up various beakers with various dilutions of water and sucrose. Cut

equal sized amounts of potato chips and place them in each one. Take

the mass beforehand, and the mass afterward, and depending on the dilution of water, it will change depending on the mass. Where

there is the least mass change, is where the water potential of the solution is similar to that of the

potato.

• Temperature.• Concentration.• Surface area.• Difference in concentrations

What is urea and urine? And what are three of your

excretory organs?

What is the path fro the kidney to urethra, and what are each of the parts, and

what do they do?

Describe the structure of a nephron and the function of

the parts.

Explain how glucagon and insulin regulate blood

glucose levels.

How does ADH regulate the water content in blood? Mention the negative

feedback.

Define homeostasis.

Explain what in your skin happens when the

temperature is too hot or too cold?

How do hormones vary from receptors?

Kidney (Filters blood and absorbs nutrients and water.

while expelling waste)→Ureter →Bladder →Urethra

• If you have hyperglycaemia (blood glucose too high), your pancreas detects it, secretes insulin which enables glucose to be used up in respiration and convert excess

glucose to glycogen.• If too low, your pancreas detects and

releases glucagon which causes glycogen to be broken down into

glucose. Both are negative feedbacks.• This is necessary, because too high or

too low blood sugar results in an inadvertent osmotic effect.

Homeostasis is the maintenance of a constant internal environment which is stable and lets an organism be independent of its external

environment.

Hormonal communication takes longer, with receptors it is

much quicker more responsive and instantaneous.

• Urea: Formed in the liver from the breakdown of excess amino acids .• Urine: Urea + Water + Salts.

• Excretory organs:• Lungs: Excrete carbon dioxide from

respiration• Kidney: Urea in urine storied in bladder

excreted through urethra. Made up of 1 million nephrons.

• Skin: Urea excreted during sweating.

The renal artery connects to an arteriole which brings blood to the glomerulus. The

glomerulus/glomerular capillaries lie inside the bowman’s capsule, and because pressure is so high, there is ultrafiltration of the blood, which

forms glomerular filtrate as it is formed of water, glucose salts, amino acids and urea. Proteins and

larger molecules do not fit. The glucose and amino acids are reabsorbed back into the blood in

the proximal convoluting tubule via active transport and a lot of water is too. More water is reabsorbed in the Loop of Henle, and the distal convoluting tubule and collecting duct reabsorb water back into the blood, the permeability of

which is affected by ADH. Any waste (urine) goes through the duct into the ureters to be excreted.

• If the concentration of blood in the body is too high, the hypothalamus in

the brain detects it. The pituitary gland secretes ADH (anti-diuretic

hormone) which binds to receptors in the distal convoluted tubule and the

collecting duct to make it more permeable so more water can be

reabsorbed which is detected by the hypothalamus, and is an example of a

negative feedback.• Too low, and less ADH is secreted.

• If you get too hot, your thermoregulatory system deals with it. Sweat is secreted onto the skin from

sweat glands, and as it evaporates you are cooled, Your blood vessels

vasodilate. This means shunt vessels shut and vessels dilate to allow blood to the surface capillaries so more heat is

lost.• When it is too cold, your shunt vessels

open vessels vasoconstrict so blood doesn’t flow to surface and heat is not

lost.

What two parts do the nervous system contain?

What are receptors.

Describe the path from receptors to performing an

reflex activity

Describe what happens when you touch a hot

object.

Describe a synapse and how it works.

What are effectors?

Give examples of reflex actions

Describe a sensory nerve, relay nerve and a motor

neurone.

• Receptors detect a change in the environment

(stimulus) and produce electrical impulses in

response. They respond to a type of stimuli. E.g. touch, chemicals, taste, light or

sound.

When you touch a hot object, touch receptors register it and send a

signal via nerve impulses to sensory nerves. These send signals about the change in stimuli to the relay nerve in the spinal cord and that sends a signal to the motor

neurone to perform a reflex action which jerks your hand away.

• Effectors are parts of the body - such as muscles and glands. Such as a

gland releasing a hormone, or a muscles

moving an arm.

• A motor neurone has a nucleus surround by a cell body with dendrites on the end. The body is connected to an axon surrounded by a fatty myelin

sheath which is connected to an effector.

• A sensory neurone looks the same, but the nucleus is surrounded by just a cell

body in the middle, with receptor endings on one end and dendrites on

the other.• A relay nerve is just a cell body with a

nucleus and dendrites.

• Central Nervous System – Brain and spinal cord.

• Peripheral nervous system – Nerve cells from CNS/to CNS

around the body.

Receptors (receive a stimulus) → Nerve Impulse (what detects the

stimulus)→ Sensory Nerve (sends signals to the relay nerve toward CNS) → Relay Nerve (in the spinal cord, it sends a signal to the motor neurone) → Motor neurone (sends

signal from the CNS to the effector) → Effector (produces a response)

A synapse is the gap between nerve cells. Neurotransmitters cross these by diffusing across the synapse and

transmitting the signal. It is secreted from vesicles which bind to receptors on the other nerve,

which generates the signal.

• Sneezing• Coughing• Vomiting• Blinking

• Withdrawal reflex

What are: Rods, cones, the iris, pupil, conjunctiva, lens,

optic nerve, retina, suspensory ligament, cilia

and fovea?

What happens to your eyes during dim light and during

bright light?

What happens to your eyes when looking at a distant object and a near object?

What are tropisms and how are plants positively

phototropic and positively geotropic?

What is the chemical that causes plants to grow? And

where is it produced and how does light affect it?

Describe experiments to show that auxin is needed

for growth.

Describe experiments to show that auxin can work in

part of a leaf.

Describe an experiment to show that plants are also

geotropic.

Bright light: Radial iris muscles relax, circular ciliary muscles

contract, pupil appears smaller.Dim light: Radial iris muscles

contract, circular ciliary muscles relax, pupil appears larger.

A tropism is a movement in a plant towards or away stimulus. Plants

move towards light and are therefore positively phototropic,

and move away from gravity so are negatively geotropic.

Have a control stem. Have another stem, but cut off the tip and put it on a mica

sheet on top of the stem. There will be no growth. However place a third tip on agar

jelly and it will grow, as auxin diffuses through it.

Place a plant on its side on a clinostat, but with the drum stopped. It will grow

upwards. Do the same with another plant on a clinostat, but have the drum rotating.

As the plant becomes confused and is constantly trying to go upwards, it will

spiral.

Rods: Sensitive to dim light giving black and white vision.

Cones: Sensitive to colour and there are red, green and blue cones.

Iris: Circular, radial muscles which regulates light by contracting as ciliary muscles relax.

Optic nerve: Sends impulses to visual cortex. Retina: Light receptors at back of eye.

Suspensory ligament:Ciliary muscles: Circular muscles around the eye

which relax as iris contracts.Fovea: Centre of retina, where light is focused.

Lens: Focuses light onto retina.Suspensory ligaments: Holds pupil in place.

Conjunctiva: Protects pupil.Cornea: Refracts light.

Distant object: Rays don’t need to refract that much so: Ciliary

muscles relax which stretches suspensory ligaments, which makes

the lens flat and thin. Muscle tension is high.

Near an object: Because near an object there needs to be more refraction: The ciliary muscles

contract, which relaxes the suspensory ligament and makes the

lens fatter and rounder.

Auxin is the chemical which causes plant to grow. It is only found in the

tips of stems and shoots. Light destroys Auxin, which means that

the shaded part grows and forces a plant to grow towards the sun.

Cut of the tip of a stem, and place the tip on only half of the stem. The auxin will only work on that side, and it will bend to

the side.