GCSE Chapter 1 Flashcards
What is a eukaryotic cell
Cells that are complex and have a nucleus and other membrane bound organelles.
An example of eukaryotic is animal and plant cells.
What is a prokaryotic cell
Prokaryotic cells are smaller and simpler cells that lack a nucleus and other membrane bound organelles.
An example is bacteria cells.
List all the sub cellular structures in animal cells
Nucleus
Cytoplasm
Cell membrane
Mitochondria
ribosomes
List all the structures of plant cells
Nucleus
cytoplasm
cell membrane
mitochondria
cell wall
chloroplasts
vacuole
ribosomes
What subcellular structures do bacteria cells have
Chromosomal DNA
plasmid DNA
flagellum
cell wall
cell membrane
cytoplasm
ribosomes
What does the nucleus do
Contains genetic material that controls the activities of the cell. Genetic material is arranged into chromosomes.
What does the cytoplasm do
It’s a gel-like substance where most of the chemical reactions happen.
It contains enzymes that control these reactions.
What does the cell membrane do
Holds the cell together and controls what goes in and out
What does mitochondria do
These are where most of the reactions for aerobic respiration take place.
Respiration transfers energy that the cell needs to work.
What do ribosomes do
Protein synthesis
what does the cell wall do
It’s a rigid structure made of cellulose. It supports and strengthens the cell
What does the vacuole do
Contains cell sap (a weak solution of sugar and salts)
It maintains the internal pressure to support the cell.
what does Chloroplasts do
This is where photosynthesis takes place.
They contain a green substance called chlorophyll, which absorbs the light needed for photosynthesis
What does a flagellum do
This is a long hair-like structure of hat rotates to make the bacterium move
What are specialised cells
A cell that performs a specific function
eg. egg sperm cell
What is the function of the tail of a sperm cell
For movement, so that it can ‘swim’ to the egg
What is the function of the mitochondria of a sperm cell
Sperm cells have lots of mitochondria in its middle section to provide energy needed to swim the distance from the sperm to the egg
what is the function of the acrosome
Stores enzymes that the sperm needs to digest its way through the membrane of the egg cell
What is the specialised function of the cytoplasm in an egg cell
It contains nutrients in the cytoplasm to feed the embryo
What happens to the membrane of the egg cell after fertilisation
It’s membrane changes structure to stop any more sperm coming in. This makes sure the offspring end up with the right amount of DNA.
What is the function of ciliates wphilial cells
They move substances and are found lining the surface of organs
What is the difference between light microscopes and electron microscopes
Light microscopes
-use light and lenses
- let us see individual cells and larger subcellular structures
Electron microscopes
-use electrons
-have a much higher magnification and resolution
-used to view subcellular structures
Formula to work out magnification
Image size = magnification x actual size
conversion scale
millimetre
micrometer
nanometre
picometre
x1000 going down
/1000 going up
How do you prepare a slide
Add a drop of water to a clean slide this will secure the specimen in place.
Use tweezers to place a piece of epiderma tissue onto the slide.
Add a drop of iodine. iodine is a stain, so it will add colour to the cell, making it easier to see.
Place a cover slip over it and make sure there are no air bubbles
How to use a microscope
Start by clipping the slide onto the stage
select the lowest powered objective lens
use the coarse adjustment knob to move the stage up
look down the eyepiece
adjust the focus with the fine adjustment knob until it’s clear
adjust to higher objective lens if it isn’t zoomed in enough
what are enzymes
Biological catalysts that speed up reactions without getting used up
What is the relationship between active site and substrate
Every enzyme has an active site with a unique shape.
A complimentary substrate has to pair with it for the reaction to be catalysed.
what 3 things change the rate at which enzymes work and when they denature
Temperature (too hot it denatures)
substrate concentration (rate of reaction increases until a certain point when it stays the same)
Ph (the optimum ph varies with different enzymes)
how do you work out the rate of reaction
1000/ time
how do you test for sugars
Benedict’s solution
how do we test for starch
iodine solution
how do you test for proteins
buiret
how do you test for lipids
ethanol
What is calorimetrey
when food is burn to see how much energy is in it
How do you work out the total amount of energy in food
mass of water x temperature change in water x 4.2
how do you work out the energy per gram of food
energy in food/ mass of food
What is diffusion
the spreading out of particles from an area of higher concentration to an area of lower concentration
