CELLS AND MOLECULES Flashcards
NUTRITION
- all need
- plants make ther eown
- animals feed on other organisms
- protiens for growth
GROWTH+DEVELOPMENT
- growth-increasing in size
- developing- becoming more complex
RESPIRATION
- release of energy from nutrients
- inside cells
EXCRETION
- removal of waste chemicals made inside the body
- e.g breathing out CO2
REPRODUCTION
-making new individuals of the same species
MOVEMENT
-only living organisms can move their bodies or parts of of their bodies
SENSITIVITY
-can sense change in their surroundings and react
CONTROL INTERNAL CONDITIONS
-e.g animals can control their heart rate, body temperature and blood and glucose levels
LEVELS OF ORGANISATION
ORGANELLE-parts of the cell CELL TISSUE- a group of simialr cells working together for 1 function ORGANISM-a human being ORGAN-mafde of tissue
CELL MEMBRANE
allows what comes in or out of the cell
CELL WALL
hold the structure of the cell like a skeleton
CYTOPLASM
were chemical reactions take place
NUCLEUS
hold the DNA+genes
controls what the cell does and when
MITOCHONDRIA
releases energy from food
were aerobic respiration happenes
CHLOROPLASTS
traps energy from sunlight
contains chlorophyll
this is then used for photosynthesis
RIBASMES
very small
were protiens are made by joining amino acids
3 WAYS SUBSTANCES INTO AND OUT OF CELLS
- diffusion
- osmosis
- active transport
DIFFUSION
- movement of molecules or particles from a HIGH to LOW concentration
- e.g oxygen from the air in the alveoli into the blood
OSMOSIS
the movement of water molecules across a semi-permable membrane.
- HIGH h2o concentration to a LOW h2o concentration
- to much water in red blood cell-swelling
- to little water in red blood cell-the plasma won’t absorb oxygen very well.
ACTIVE TRANSPORT
this is the movement of molecules into a cell against a concentration gradient
- LOW TO HIGH concentration
- need energy from respiration
e. g mineral ions from soil into root hair cells of plants
TEST FOR STARCH
- add a few drops of iodine
- brown to black = starch is present
TEST FOR PROTEIN
- add 1cm3 of Biuret reagent
- blue to purple=protein is present
TEST FOR GLUCOSE
- add 1cm3 Benedicts reagent
- place in hot water bath (70°c-80°c) for 3-5 minutes
- blue to green=some glucose
- blue to red=lots of glucose
TEST OF OSMOSIS
-pure water and potato slice
-water moves to potato cells
-potato mass would increase
>put potato in sugar solution
>water moves out of cell by osmosis
TEST OF DIFFUSION
- agar blocks of jelly
- colour change from green to red
