Weaknesses: Flashcards
Define active transport
The movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy.
What is the test for lipids?
Emulsion test
Clear to milky white
What is the test for sugars?
Benedict’s test
Colour change of blue to brick-red
What is the role of the liver in terms of respiration?
The liver is where lactic acid is broken down
What is radiotherapy?
When cancer cells are destroyed by concentrated doses of radiation
What 5 defences do plants have to disease/herbivores?
Poisons Thorns Hairy stems Drooping leaves Mimicry
What is gonorrhoea?
A bacterial STD. Symptoms include a green discharge.
How are capillaries adapted?
- One cell thick
- Carry blood very close to cells
- Permeable walls
How does the heart work?
1) deoxygenated blood flows into the right atrium via the vena cava
2) the right atrium contracts forcing the blood into the right ventricle, through a tricuspid valve
3) the ventricle contracts, forcing the blood into the pulmonary artery. From here, the deoxygenated blood goes to the lungs
4) at the same time, oxygenated blood is returning from the pulmonary vein into the left atrium.
5) the atrium contracts, forcing the blood through a bicuspid valve into the left ventricle.
6) the ventricle contracts, meaning blood is pushed into the aorta from which it is circulated
What is an independent variable?
The thing being tested
What is the test for proteins?
The biuret test
Blue to pink or purple
What does a stent do?
It pushes the artery wall out, squashing fatty deposits.
What 4 ways can society help stop the spread of antibiotic resistant bacteria?
- Complete courses
- Don’t over-prescribe
- Don’t give animals too much antibiotics
- Don’t ask for antibiotics
What is Tobacco Mosaic Virus?
A virus that effects plants. It causes plants to be discoloured so they cant photosynthesise.
How are veins adapted?
- Bigger lumen
- Thinner walls
- Valves
What is the equation for anaerobic respiration?
Glucose = lactic acid + energy
What is the role and adaptation of the palisade layer?
Where most photosynthesis takes place. Has lots of chloroplasts.
What are the stages of how a pregnancy test works?
1) urine passes through reaction zone
2) HCG (hormone in urine) binds to mobile HCG antibody which is connected to the blue dye
3) HCG moves up the stick and binds to immobile HCG antibodies in result zone
4) other antibodies which do not bing to HCG bind to antibodies in control zone
5) blue dye appears in both zones
What do proteases do?
They convert proteins into amino acids
Why do multicellular organisms need exchange surfaces?
They have a smaller surface area : volume ratio
What is a prokaryote?
A cell that doesn’t have a true nucleus
How are the alveoli adapted for gas exchange?
- Large SA
- Moist lining
- Thin walls
- Good blood supply
Define differentiation
The process by which a cell changes to become specialised for its job
Where is amylase made?
- Salivary glands
- Pancreas
- Small intestine
What is Malaria?
A disease caused by a protist. It causes repeating episodes of fever. It is spread by the vector, mosquitos.
How do enzymes work?
The active site of an enzyme will only fit to one substrate
The substrate fits into and binds to the enzyme
The enzyme breaks it down and releases the products
The enzyme does not get used up so can be used in other reactions
Where are proteases made?
- Stomach (pepsin)
- Pancreas
- Small intestine
Where did digitalis come from?
A chemical found in foxgloves
How do you make monoclonal antibodies?
1) Mouse injected with antigen
2) Fuse mouse lymphocyte with a tumour cell to create a hybridoma
3) Hybridoma clone to get lots of identical cells.
4) Collect and purify the antibodies
What is the effect of drinking alcohol whilst pregnant?
The alcohol passes through the placenta into the baby. It can lead to miscarriages and deformities.
Define osmosis
The movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration
How are root hair cells specialised?
Big surface area
Thin walls
Lots of mitochondria to produce energy for active transport
What is the role and adaptation of the stomata?
Lets CO2 diffuse directly into the leaf. Controlled by guard cells to respond to changes in environment.
What is the equation for aerobic respiration?
C6H1206 + 6O2 = 6CO2 + 6H20 + energy
What is the formula for light intensity?
1/d^2
What is the oxygen debt?
The amount of oxygen required to turn the lactic acid into carbon dioxide and water
How big are prokaryotic cells generally?
0.2-2nm
What is salmonella?
A bacterial disease which causes fever, stomach cramps, vomiting and diarrhoea. It is caused by eating food that had the disease when it was alive.
What are the 3 main ways that pathogens can be spread?
- Water
- Air
- Contact
What is a causal mechanism?
Something that explains how one factor effects another