Cell structure, Variety of Life, Levels of organisation. Flashcards
Define nutrition
ability to absorb nutrients for energy and cell growth and repair
what is respiration
ability to produce energy from food molecules such as glucose
what is excretion
removal of metabolic waste from the body
what is sensitivity
the ability to detect change and respond to environment
what is movement
ability to change location of part of the body
what is homeostasis
ability to maintain a stable internal environment
what is reproduction
ability to produce offspring
what is growth
a permanent increase in size due to increase in cell number
define prokaryotic
organisms that do not contain membrane bound organelles e.g. bacteria
define eukaryotic
organisms containing membrane bound organelles e.g. animals, plants and fungi
what is the role of the nucleus
controls cell activity and contains genetic material
what is the role of the cell membrane
forms the outer surface of the cell and controls movement in and out of the cell
what is the role of the cytoplasm
gel like substance that is the site of chemical reactions
what is the role of ribosomes
site of protein synthesis
what is the role of mitochondria
site of aerobic respiration
what is the role of chloroplasts
site of photosynthesis
what is the role of the cell wall
rigid structure that supports and strengthens the cell
what is the role of the vacuole
large organelle that supports cell rigidity and structure
what is a tissue
group of similar cells that work together to carry out a function
what is an organ
a group of tissues that work together to carry out a function, they work together to form organ systems
describe the structure of fungi
single celled, chitin cell wall, feed by saprotrophic nutrition, and store carbs as glycogen
how do plants store carbs
sucrose or starch
what is saprotrophic nutrition
secretion of extracellular enzymes into the area outside their body to dissolve food so they can absorb their nutrients
describe the structure of protoctists
single celled organisms, some contain chloroplasts
describe the structure of bacteria
single celled, no nucleus, circular chromosomes, feed of other organisms
describe the structure of viruses
non living, smaller than bacteria, reproduce when on host cell, protein coat rapped around some genetic material, infect other organisms
what is a catalyst
a substance that increases the rate of reaction without being used up
describe the lock and key theory
active site and substrate join to form enzyme substrate complex, the products are then released, enzyme active site is very specific
explain the effects of temperature and PH on an enzyme
if temperature is too high, then enzyme denatures and active site no longer able to join with substrate. if PH is too high or too low then enzyme denatures.
how to measure the rate of reaction using the enzyme catalase on the breakdown of hydrogen peroxide into water and oxygen
use pipette to add a set amount of hydrogen peroxide to a boiling tube, set the temp. to 10 degrees, add catalase to the hydrogen peroxide and quickly attach the bung, record amount of oxygen produces in a minute, and repeat 3x, record for 20, 30, 40 degrees
how to measure how fast the substrate disappears using the enzyme amylase to breakdown starch to maltose
use iodine solution, if starch is present, the solution will turn from brown orange to black
what is diffusion and what substances are too big to pass across the cell membrane
the net movement of particles from an area of high concentration to an area of low concentration, large molecules such as starch and protein are unable to pass the membrane
what is osmosis
the net movement of water molecules across a partially permeable membrane from an area of higher water concentration to region of lower water concentration. substances such as sucrose are unable to pass.
how can you investigate diffusion in non-living systems
make agar jelly with phenolphthalein and dilute sodium hydroxide
put some dilute hcl in a beaker, cut out a few cubes of the agar jelly and put them in the beaker with the acid, eventually the cubes will go colourless as the acid diffuses into the jelly and neutralises the sodium hydroxide.
what happens to potato cylinders if
- they draw in water
- they draw out water
in-get longer
out-shrunk
what is active transport
the active movement of particles against the concentration gradient from an area of low concentration to an area of high concentration using energy from respiration
