part 1 Flashcards
word equation for photosynthesis
carbon dioxide + water = glucose + oxygen
describe how energy for photosynthesis is gained by plants
- light shines on palisade layer
- palisade cells of palisade mesophyll tissue has lots of chloroplasts
- contains chlorophyll absorbs sunlight
how did the student deal with the anomylous result?
- observe scale better
- ask someone else to read it
give one factor the students should have kept constant in this investigation
light intensity
why did the rate of photosynthesis decrease from 35 to 40 degrees?
the enzymes are damaged
what is diffusion?
the random movement of particles from an area of high concentration to an area of low concentration until equilibrium is reached
what increases the rate at which carbon dioxide diffuses into the mesophyll cells?
- decreased chloroplasts
- stomata
explain how the lungs are adapted for efficient exchange of gases by diffusion
- contains alveoli and surrounded by network of blood capilleries
- maximises diffusion of substances
- give lungs large surface area:more contact
- thin walls: shorter diffusion distance
- moist, permeable walls: gas dissolve
- extensive blood supply: deoxygenated blood to lungs, oxygenated away
- large diffusion gradient: higher concentration oxygen in alveoli move to blood
how does root hair cell use active transport?
- carrier proteins in cell membrane
- absorb nitrate ions from dilute solution in the soil
- against a concentration gradient
- uses energy from respiration
similarities between prokaryotic and eukaryotic cells
- cytoplasm
- ribosomes
give 3 differences between the prokaryotic and eukaryotic cell
- prokaryote has a single loop of dna and plasmids
- prokaryote has no chloroplasts but mesophyll cell does
- prokaryote is smaller
ratio between bacteria and mesophyll cell
- 0.05 is 50 micrometers
- 1:50
what is stage 1 of the cell cycle?
- interphase
- dna spreads out in long strings
- before divides, cell grows and increases subcellular structures eg mitochondria
- duplicates DNA forms X-shaped chromosomes
what is stage 2 of the cell cycle?
- chromosomes line up at centre
- cell fibres pull them apart
- two arms of each goes to opposite ends of cell
- nucleus divides as membrane froms around two nuclei
what is stage 3 of the cell cycle?
- cytoplasm and cell membrane divides
- two daughter cells
- same dna
- identical to parent cell
explain the ‘lock and key’ method
- substrate collides with enzyme which fits the shape of the active site
- enzyme catalyses break down of the substrate
- enzyme left unchanged and releases products from active site
why does each different type of lipase act on only one specific type of liquid molecule?
active site complimentary to a specific lipid
how do you use the Benedict’s test to test for glucose?
- prep food sample and transfer 5cm3 to test tube
- set waterbath at 75° C
- add 10 drops Benedict’s solution using pipette
- place test tube in waternath using test tube holder and leave for 5 mins pointing way
- blue to yellow/green/brick-red
how do you use iodine solution to test for starch?
- prep food sample and transfer 5cm3 to test tube
- add few drops iodine solution to test tube and gently shake to mix contents
- browny-orange to blue-black
how does the leaf contain glucose aswell as starch?
- photosynthesis: chlorophyll asborbs sunlight
- allows CO2 and water converted into glucose
- turned into starch for storage
why does plant still have glucose in the dark but not starch?
- no light for photosynthesis
- consumption of all stored starch
- glucose transported to growing parts of plant for respiration
what type of defense response are thorns?
mechanical
what type of defense response are poisonous berries?
chemical
give two reasons to why plants get yellow leaves and stunted growth?
- tobacco mosaic virus: discolouration on leaves, cant carry photosynthesis aswell affecting growth
- magnesium ion deficiency: required to make chlorophyll causes less green pigment
how does nodules benefit bacteria?
- next to the stem/phloem
- gets more glucose from plant for food
how does nodules benefit plants?
- produces nitrogen compounds helps the plant to grow and compete
- dies: the fixed nitrogen releases available to other plants
- helps fertilize soil
suggest two other factors scientists would have controlled?
- diet
- mental health
describe the effects of liver failure on the human body
- wont be able to detoxify harmful substances in body and will damage healthy cells/tissues/organs
- bile is produced here, stored in galbladder and released in s.i, neutralises acidic hydrochloric acid in stomach as its alkaline + emulsifies fat
- wouldn’t be able to digest properly
how do you use dye to see pathogens on the slide?
stain antibodies with dye so when they bind to pathogens they are easy to locate
how does increased phagocytosis help patients?
- phagocytes engulf more pathogens
- digests them at a quicker rate
- improving health of patient
- passes test on animals then tested on human volunteers
- healthy to check harmful side effects (very low dose increases)
- good results: tested on ill to find optimum dose
- test how well: give drug and placebo to 2 groups so doctor sees actual difference drug makes
- double-blind trials: doctor analysing results aren’t subconsciously influenced by their knowledge
why are mAbs made by mice unsuccsessful?
human body more familiar with human cells
