Key Concepts Flashcards
What Is a Eukaryotic cell!?
contains a nucleus and other structures.
They are surrounded by membranes
What type of microscope can you see mitochondria with!?
A light microscope but not in detail
What type of microscope can you see ribosomes with!?
An electron Microscope
What is the function of CYTOPLASM in an animal cell!?
contain dissolved nutrients, salts and organelles.
Many chemical reactions occur here!!!!
What is the function of a NUCLEUS in plant and animal cells!?
Contains genetic material including DNA, which controls cell activity
What is the function a a cell membrane in plant and animal cells!?
Permeable to some substances
Controls the movement of substances which go in and out of the cell
What is the function of MITOCHONDRIA in plant and animal cells?
contain the enzyme for respiration
What is the function of RIBOSOMES in plant and animal cells!?
They are tiny structures and protein synthesis occurs here!
Are plant cells Eukaryotic or prokaryotic!?
Eukaryotic
What 4 structures do both plant and animal cells share!?
-a nucleus
-a cell membrane
-mitochondria
-ribosomes
What 8 structures do plant cells contain!?
Cytoplasm
A nucleus
Cell membrane
Mitochondria
Chloroplast
A cell wall
A permanent vacuole
Ribosomes
What do 8 structures do plant cells contain!?
A nucleus
A cell membrane
Chlorophyll
Mitochondria
Ribosomes
Chloroplast
Cell wall
Permanent vacuole
What is the function of CHLOROPLAST in a plant cell!?
contains the green pigment (chlorophyll) which absorbs the light energy.
Contains the enzymes needed for photosynthesis.
What is the function of CHLOROPHYLL in a plant cell!?
Green pigment that absorbs light energy
What is the function of THE CELL WALL in a plant cell!?
Provides structure and protection
Does an animal cell contain a cell wall!?
No
Does a bacterial cell contain a cell wall!?
Yes-not made form cellulose
What is the function of the PERMANENT VACUOLE in a plant cell!?
Is filled with cells that help to keep the cell’s shape.
Do animal cells contain a permanent vacuole!?
No- but they may contain one that is Small and temporary
Are bacterial cells Eukaryotic or Prokaryotic!?
Prokaryotic- they are single celled
What is a prokaryotic cell!?
does not contain a nucleus or any other structures
none are surrounded by membranes
Are bacterial cells visible underneath a microscope!?
Only larger bacteria are visible underneath a light microscope
HOWEVER……
Electron microscopes would be needed to see the cell in detail.
What structures do plant, animal and bacterial cells share!?
Cytoplasm
Cell membrane
What is the function of CHROMOSOMAL DNA in a bacterial cell!?
The same as DNA
not contained by a nucleus it is found loose in the cytoplasm
What is the function of PLASMID DNA in a bacterial cell!?
Are small, closed-circles of DNA that are present in the cytoplasm
They can move from one bacterial cell to another unlike CHROMOSOMAL DNA . This provides variation
What is the function of the FLAGELLA in a bacterial cell!?
They rotate OR move in a whip like motion to move the bacterium.
What is the word of one flagella!?
Flagellum
What is the function of the CELL WALL in a bacterial cell!?
Provides protection- isn’t made from cellulose
How do bacterial cells duplicate!?
They copy themselves by binary fission
What is binary fission!?
Very similar to mitosis but as the cell is PROKARYOTIC it is given a different name
How big is a EUKARYOTIC CELL!?
Between 5um-100um.
How big is a PROKARYOTIC cell!?
Between 0.2um-2.0um.
What are the outer layers of a EUKARYOTIC cell!?
Cell membrane which is surrounded by a cell wall ( cell wall=plants a fungi)
What are the outer layers of a PROKARYOTIC cell!?
A cell membrane surrounded by a cell wall
What structures does a EUKARYOTIC cell contain!?
Cytoplasm
Mitochondria
Chloroplast (plants)
Ribosomes
What structures do PROKARYOTIC cells contain!?
Cytoplasm
Ribosomes
NO….
mitochondria
Chloroplast
Where is the genetic material found in a EUKARYOTIC cell!?
-DNA found in the nucleus
- plasmids are found in a few eukaryotic organisms
Where is the genetic material found in a PROKARYOTIC cell!?
-DNA is is a single molecule:found free in the cytoplasm
- additional DNA found in plasmids
What is a plasmid!?
One or more rings of DNA
What type of cell division occurs in a EUKARYOTIC cell!?
Mitosis
What type of cell division occurs in a PROKARYOTIC cell!?
Binary fission
What is a specialised cell!?
Each cell is specialised to carry out a particular role to ensure the organism functions as a whole
-animals and plants therefore consist of many different types of cells working together
Name 2 examples of a specialised animal cell!?
Egg and sperm
Is a sperm cell HAPLOID or DIPLOID!?
Haploid
What is found in the HEAD of a sperm cell!?
Contains genetic material for fertilisation in HAPLOID nucleus
What is found in the ACROSOME of a sperm cell!?
Contains enzymes that sperm can penetrate egg
Where is the ACROSOME in a sperm cell found!?
In the head
What is found in the MIDDLE PIECE of a sperm cell!?
It is packed with mitochondria which are used to release energy needed to swim to and fertilise the egg
What is the use of the TAIL on a sperm cell!?
It enables the sperm to swim
Name a Fact about sperm cells……..
Sperm are the smallest cell in the human body and millions are made
What does an EGG cell contain!?
Cytoplasm
HAPLOID nucleus
Cell membrane
What is the job of the CYTOPLASM in an EGG cell!?
Contains nutrients for growth of the early embryo
What is the job of the HAPLOID nucleus in an EGG cell!?
Contains the genetic material for fertilisation
What is the job of the CELL MEMBRANE in an EGG cell!?
Changes after fertilisation by a single sperm so that no more sperm can enter
Fact about EGG cells……
Egg cells are one of the largest cells in the body and only a few are made
What are the job of the CILIA in a CILIATED EPITHELIAL CELL!?
Cilia are found on the surface and Beat to move fluids and particles up the trachea.
What are light microscopes used for!?
Used to study living cells and are for regular use when magnitude and resolution is relatively low
What are electron microscopes provide!?
Provide higher magnification and resolution images
Cannot used to see living cells
When was the first microscope discovered!?
It is unknown
What year was the compound microscope made in!?
1590s
Who invented the compound microscope!?
Dutch spectacle maker- Janssen
What was the compound microscope!?
Lenses in tubes
What is the magnification of the compound microscope thought to be!?
Between x3 and x9
How was he compound microscope used in the 1650s!?
It was used to observe and draw cells
Who used the compound microscope in the 1650s!?
Robert Hooke
Who created a microscope with a single spherical lens!?
Antonie Van Leeuwenhoek
What magnification did the single spherical lens microscope have!?
x275
What is the maximum magnification of a light microscope!?
x2000
What is the top magnification of a light microscopes when being used in schools!?
x400
What is the calculation for the MAGNIFICATION of a LIGHT microscope!?
Magnification of eyepiece x magnification of objective
What is the calculation for the magnification of an image when using a LIGHT microscope!?
Size of image
————————-
Real size of object
What is the only important factor to viewing cells!?
Magnification
Other than magnification what is another important factor when viewing cells with a light microscope!?
Resolution
What is the resolution!?
The detail that can be seen
The greater the detail in an image depends on what!?
Resolution or resolving power
What is the resolution of a light microscope!?
Around 2um OR 200nm
What does this resolution number mean!?
It Means it cannot distinguish points closer than 200nm
What does nm stand for!?
Nanometre
How much of a meter is a nanometre!?
1 billionth
How is one nanometre written as!?
1x10-9m or 1/1000 000 000
What does an election microscope use to see an image!?
Uses a beam of electrons instead of a ray of light.
What cannot be observed with an electron microscope!? And why!?
Living cells
because samples are placed into a vacuum
What are the 2 types of electron microscope!?
TEM: transmittion electron microscope
SEM: scanning electron microscope
What is a TEM microscope used to examine!?
Thin slices or sections of cells or tissues
How big is the depth of field in an SEM and what is it used for!?
Large depth of field
Used to examine the surface structure of specimens
What is the maximum magnification of a TEM!?
Around x1 000 000
What does this large magnification of a TEM mean!?
Images can be enlarged beyond that photographically
What is the limit resolution of an TEM!?
Less that 1nm
What does the 1nm resolution reveal!?
Structures that are not visible with a light microscope
What is the magnification of a SEM!?
Up to x30 000
What is the limit of resolution of an SEM microscope!?
Lower than a TEM at around 50nm
What are enzymes!?
Enzymes are proteins that function as biological catalysts
They are molecules that speed up a chemical reaction without being changed themselves
What shape are enzymes!? And what do they allow!?
Folded complex 3D shapes
allow smaller molecules to fit into them
What is the place where the molecules fit into the enzyme called!?
The active site
In the lock and key hypothesis what 2 shapes match together!?
The shape of the active site matches with the site of the substrate
What makes the enzyme highly specific!?
The active site shape and the substrate shape match together
How many types of reaction can an enzyme catalyse in!?
Usually one but some catalyse by a few types of reactions
What is the first step not the lock and key process!?
The substrate collides with the active site of the enzyme and becomes attached to the
What does the active site have to the substrate on the first step of lock and key!?
A complementary shape