Cells Flashcards
(30 cards)
Define an independant variable
Something you measure. It will change
Define dependant variables
Things that must remain the same
What are the characteristics of living things
Move
Reproduce
Synthesise
Grow
Respire
Excrete
Nutrition
Define a cell
Smallest independent unit of life
Name the organelles of a plant cell
Nucleus Chloroplast Golgi apparatus Cell wall Cell membrane Mitochondria Ribosome Vacuole Cytoplasm
Name the organelles in an animal cell
Golgi apparatus Cytoplasm Cell membrane Mitochondria Nucleus Vacuole Ribosome
List the differences between plant cells and animal cells
Plant has cell wall, animal does not
Plant cell has a squarish shape, animal cell rounder
Plant has chloroplast, animal does not
Plant cell has a large vacuole, animal cell has small vacuole
Define the cell membrane
Surrounds every cell and controls what enters and exits the cell.
What is the molecular formula of glucose
C6H12O6
Define diffusion
The passive movement of molecules along a concentration gradient from and area of high concentration to an area of low concentration.
Define passive
No energy needed
Define osmosis
The passive movement of water molecules through a semi-permeable membrane from an area of high water concentration to an area of low water concentration
Define active transport
The active movement of molecules against a concentration gradient from an area of low concentration to an area of high concentration.
Define autotrophs and heterotrophs
Autotrophs photosynthesise and make their own food.
Heterotrophs have to consume their food for energy
What does photosynthesise transform
Light energy to chemical energy
Where does aerobic resperation occur
In the mitochondria
What is step one of aerobic respiration and what is its formula
Glycolysis
C6H12O6 -> 2C3H6O3 + 2ATP
*no oxygen
What is the second step of aerobic respiration and what is its formula
Respiration
2C3H6O3 +6O2 -> 6CO2 + 6H2O + 36 ATP
When does anaerobic respiration occur. Where does it occur and what is its formula
When no oxygen is present. It is also called fermentation
It occurs in the cytoplasm
C6H12O6 -> 2C3H6O3 + 2ATP
(Pyruvate) or lactic acid
How do you set out a hypothesis
If the independent variable is changed, then the dependant variable will change
Define an enzyme
Biological catalysts - they speed up chemical reactions in cells
Name four characteristics of enzymes
Substrate specific - catalyse only one reaction
Temperature sensitive - work only in and certain temp range
pH sensitive - work only in a certain pH
Can be reused
What are the storage organs of plants
Tubers eg potatoes Roots eg carrots Bulbs eg turnip, or garlic Fleshy stalks eg celery, or rhubarb Fleshy leaves eg spinach
How do humans store energy
Glycogen in the liver (24 hours)
Fats -> excess glucose is turned into fats and stored
