B3 moving and changing materials Flashcards
Osmosis
Diffusion of water from an area of high water potential to an area of low water potential down a concentration gradient through a partially permeable membrane
Lysis
Cells swell and burst
Crenation
Cells shrink and shrivel
Turgid
Water enters plant cell by osmosis and fills vacuole.
Vacuole pushes against cell wall
Flaccid
Water moves out of cell by osmosis, vacuole shrinks
If too much water leaves cytoplasm moves away from cell wall causing cell to be plasmolysed
Required practical- investigate the effect of a range of concentrations of salt or sugar solutions on the mass of plant tissue
Put potato chips in different concentrations of NaCl solution
Weighed before and after
Potato dried off by paper towel
They thought- the greater the concentration, the lighter the chip
Active transport
The net movement of particles from an area of low concentration up a concentration gradient to an area of high concentration through a partially permeable membrane
Catalyst
A chemical that speeds up a reaction without being used up itself
Enzymes
Biological catalysts
Help photosynthesis, respiration, protein synthesis
Enzymes help to
Break down large molecules into smaller ones
Build large molecules from smaller ones
Change one molecule into another molecule
Lock and key theory
Lock- enzyme has unique sequence or amino acids.
Active site has specific shape that substrate will fit into
Key- substrate, once it is attached to active site it becomes a product
If shape do active site changes enzyme is denatured
Enzyme controlled reactions are affected by
pH
Temperature
Collision theory
- Reactants start to collide; as collisions increase more product is made
- Enzyme added holding the reactant in place
- There is an increase in collisions between reactants; rate of reaction also increases
- Reactants are being used up and there are fewer collisions; rate of reaction decreases and amount of product levels off
Required practical- investigate the effect of pH on the rate of reaction of amylase enzymes
Uses solutions of starch and amylase in test tubes to find optimum pH required for experiment
Test tubes are put in water bath at 25 for 5 mins
pH buffer solution added to amylase first then starch
In a spotting tile iodine is added
Black/blue colour should end up orange
Repeated for different buffer solutions with different pH values
Digestive system
Long tube that runs from the mouth to the anus
Consisting of serval organs working together to digest and absorb food
Absorption
Soluble food passes through the small intestine wall into the blood
Blood transports the products of digestion to the body cells
Salivary gland
Produces Saliva
Moistens food, has enzymes to digest food
Oesophagus
Muscular walls
Moves food to the stomach by peristalsis
Stomach
Strong muscles,produces HCl acid, produces enzymes
Mix food,kills harmful microbes, provides optimum pH for stomach enzymes to digest food
Liver
Produces bile(alkaline) Neutralises stomach acid, stores carbohydrates as glycogen, emulsifies fats
Gall bladder
Small bag like structure
Stores bile
Pancreas
Produces enzymes
Provide enzymes to digest food in the small intestine
Small intestine
Produces enzymes large surface area
Digestion of food, absorption of solvable food
Large intestine
Special cells to absorb fluids
Absorbs water, solidifies waste
Anus
Strong muscle
Releases waste
Bile
Emulsifies fats into smaller droplets to increase the surface area
Large surface area and alkali pH increase rate to fat digestion into fatty acids and glycerol
Fatty acids and glycol diffuse into lymphatic system
Products of digestion uses
Glucose- respiration, make new carbs
Amino acids- synthesised/built into proteins in ribosomes. Protein synthesis catalysed by enzymes
Fatty acids/glycerol- energy,build cell membrane, make hormones
Small intestine exchange surface
7m long, lots of timed of absorption
Very thin, permeable membrane for easy diffusion
Villi and microvilli increase surface area
Blood capillaries transport molecules away maintain gradient
Between meals active transport is used
Required practical- use qualitative reagents to test for a range of carbohydrates, lipids and proteins
Glucose- Benedictus reagent, should turn orange/red
Protein- sodium hydroxide, purple
Lipid- Sudan 3 stain
Spiracles and gills
Oxygen taken in from gills (feathery and increase SA)
Tiny holes along body which open into small tubes(trachea)
Skin
Thin membrane for diffusion
Moist for dissolving gases
Usually have large SA:V
Trachea
Spiracles can close to prevent evaporation (surface moist)
Trachea have branches to increase SA
Pump air in and out of trachea
Trachea are stiffened to prevent collapse
Short diffusion distance
Gills
Feathery projections increase SA
Thin walls for diffusion
Water pumped over the gills
Lungs
Alveoli have thin membrane
A provide large SA
Moist for dissolving gases
Constant ventilation maintain gradient
Root hair cells
Found on plant roots just behind root tip
Help anchor plant
Absorb water and mineral ions from the soil
Have long thin exchange surface
Water absorbed by osmosis and active transport
Fertilisers
Contain minerals are added to the soil to improve plant growth
Root hair cells are efficient exchange surfaces as…
Large SA No cuticle, just thin membrane Thin cell wall Large vacuole Close to the xylem
Nitrates, nitrogen
Make amino acids for protein synthesis
Phosphates
Respiration
Make new DNA
Make new cell membranes
Potassium
Respiration
Photosynthesis
Make enzymes
Magnesium
Make chlorophyll for photosynthesis
Culture solutions
Contain known amounts of of specific minerals
Mineral deficiency
When a plant can’t get enough of a mineral from the soil or culture solution for healthy growth
2 types of fertilisers
Inorganic- man made. Come from concentrated sources of minerals. Don’t smell. Easy to apply and store
Organic- animal/plant matter. Take time to break down so slowly release minerals. Reduce soil erosion. Improve water retention in soil
Single circulatory system
Blood flows in one circuit around the body
Eg. Fish
Open circulation
No blood vessels, blood flows freely around body
Double circulatory system
Blood flows 2 ways round the body
From heart to lungs
Heart to rest of body
Eg. Humans
Arteries
Carry blood from heart Blood under high pressure with pulse Thick walls, not permeable Small lumen No valves Carry oxygenated blood
Veins
Carry blood to heart Blood under low pressure, flows smoothly Thinner walks, not permeable Large lumen Valves along their length prevent back flow of blood Carry deoxygenated blood
Capillaries
Carry blood form arteries to veins Pressure falls and pulse disappears Walls are one cell thick and permeable No lumen No valves Blood slowly loses oxygen
How blood flows from the heart
Heart to arteries, arterioles, capillaries, venules, veins, heart
Advantages of double circulatory system
Blood pressure is higher, especially to the body
There is a higher blood flow to body tissues
Oxygenated blood is separate from deoxygenated blood
Adaptions of blood vessels
Thick elastic walls withstand high pressure
Capillary networks large exchange SA
Thin permeable walls of capillaries, shot diffusion distance
Large lumen, least flow resistance
Valves prevent back flow of blood
The heart
Right atrium}right venticle} (pulmonary artery)} lungs}(pulmonary vein)} left atrium}left ventricle} (aorta)} body}(vena cava)}right atrium
Cardiac cycle
Heart relaxes and blood enters both atria
Atria contracts at the same time which forces blood into both ventricles
Ventricles contract from the bottom upwards which forces blood into the pulmonary artery and aorta
Plasma
Transports substances around the body, eg. CO2
Eg. Hormones, antibodies,nutrients,waste substances
Red blood cells
Carry oxygen from the lungs to the body cells
Tiny allowing them to pass through narrow capillaries
Biconcave disc shape, large SA:V
Contains haemoglobin which binds to oxygen to transport form lungs to body tissue
No nucleus, more space for haemoglobin
White blood cells
Help protect the body against infection
Platelets
Cell fragments which help the clotting process at wound sites
How blood carries oxygen
Haemoglobin binds with oxygen to form a bright red compound called oxyhemoglobin
Bonds are weak
Splits in areas of low oxygen concentrations
Breathing system
Trachea}bronchus}bronchioles} alveoli
Alveoli exchange surface
Tiny spheres, larger SA:V
Thin walls
Surrounded by blood capillaries ensure good blood supply
Moist surface
Coronary heart disease
Fatty material build up in arteries
Blood flow reduced and less oxygen and glucose reach the heart for respiration
Heart doesn’t contract properly
Symptoms of CHD
Tiredness, lack of energy
Breathlessness
Treatments of CHD
Artificial pacemakers Valve replacement High cholesterol treated with drugs, statins Stents, treat narrow coronary Heart transplant
