B 2 x Flashcards
What in most human and animal cells
nucleus: controls activities of cell and contains genetic info (DNA)
cytoplasm: liquid mixture where most chemical reactions take place (catalysed by enzymes to speed up desired reactions)
cell membrane: controls passage of substances in and out of cell
mitochondria: use oxygen and sugars to release energy for cell in aerobic
ribosomes: protein synthesis occurs using aa
Plant and algal cells
cell wall: cellulose, strength, protenction
chloroplasts: absorb light energy to make food, contain chlorophyll, green
large permanent vacuole: filled with cell sap for storage and keep cell shape
Bacterial cell
single celled organisms, less than 1ym cytoplasm cell membrane cell wall Bacterial chromosome: genes not in distinct nucleus Plasmid extra loops of DNA Flagellum: lash to move Slime capusle: added protection
Yeast
single celled fungs, 3-4ym nucleus cytoplasm membrane cell wall vacuole food storage granule
What form organisms
tissues are aggregations of similar cells
organs aggregations of tissues performing specific physiological functions
organs organised in organ systems
work together to form organisms
Tissue
group of cells with similar structure and function
Eg of tissues and specific to stomach
muscular: contract to bring about movement, chrun contents
glandular: produce substances like enzymes and hormones, produce digestive juices
epithelial tissue: covers some part of body, cover out and in of stomach
Glands
pancreas and salivary glands, prod digestive juices
Green plants and algae obtain raw materials to make food from
air (CO2) and soil (H2O)
What happen to glucose
converted into insoluble starch/glycogen, intial in leaf for darkness then root tubers as soluble so would affect osmosis
prod fat/oil for storage, build cell membranes
prod cellulose (undigested part of diet fibre), strengthen cell wall
prod proteins by using nitrate ions
Physical factors affect organisms
temp
availability of nutrients: plants longer root outcomplete
amount of light: measured with light meter in lux, tall plants outcompete
availability of water
availability of O2 and CO2
Proteins act as
structural components of tissues like muscles
hormones
antibodies
catalysts
Biological detergents contain temp con
lipase
protease
more effective at low temp
costly
Energy released in respiration used for
build larger molecules from smaller
contract muscles in animals
body temp in cold in birds and mammals
build sugar, nitrates, nutrients, to proteins in plants
Reproductive organs
testes
ovaries
When differentiate
animals early stage
plant cell retain ability all life
stem cells: human embryos and adult bone marrow to nerver cells, help paralysis
DNA
deoxyribo nucleic acid
double helix structure
Polydactyly
extra fingers or toes
dominant allele
Specialised cells
add. features to perform certain gunctions
Differentiation
ability of multi-cellular organisms to give certain cells certain jobs
What affects rate of diffusion
temp: increase KE
distance
SA
diff con
Purpose of digestive system
break down insoluble molecules to soluble so can be absorbed and used by cells
Oxygen test
collect bubbles of gas, light glowing splint
Limiting factor
when in short supply, prevent plant from growing faster