A1: Cells, Tissues, And Biological Molecules Flashcards
What does the cell membrane do?
Controls what enters and excites the cell
What does a Centriole do?
Helps the cells to divide
Cytoplasm?
.Cell like liquid containing organelles
.Gives the cell shape
.Site of many reactions
Mitochondria?
The site of aerobic respiration and its where ATP is made.
It also has a double membrane.
Nucleus?
. Every Eukaryotic cell has one
. Controls the cell by storing genetic information
Nucleolus?
Makes ribosomes
Ribosomes?
Makes up proteins out of amino acids using instructions from nucleus
Rough endoplasmic reticulum?
Layers of membrane covered in ribosomes
Smooth endoplasmic reticulum?
Layers of membrane that make lipids and carbohydrates.
Golgi apparatus??
Packages and modifies proteins ready for export from the cell.
Makes lysosomes.
Lysosomes?
Contains digestive enzymes for breaking down waste inside the cell.
Cytoskeleton?
Gives the cell shape
What does hydrophobic mean?
Repels water = fatty acid tails
What does hydrophilic mean?
Attracts water = phosphate heads
What’s a glycoproteins?
Found on the outside of the cell membrane.
Hydrophilic nature means they can function in aqueous environments.
Important for cross-linking cells and proteins e.g collagen to add strength to the tissues.
Cell recognition and communication .
Binds to hormones
What’s a glycolipid?
Maintain the stability of the cell membrane.
Cell recognition and communication.
What does cholesterol do in the cell membrane?
Regulates fluidity and stabilises the membrane ( provides support).
Chanel protein?
They make hydrophilic tunnels and allow target molecules to pass through by diffusion.
What does partially permeable mean?
Only allows particular substances to cross it.
What is a fluid Mosaic?
Phospholipid molecules move around each other within a layer relative to one another in different shapes and sizes.
Vesicle?
Transport materials around the cell or out of it.
What is a carrier protein?
Uses energy to transport substances.
Intrinsic protein
They are firmly in bedded within the phospholipid bilayer.
Extrinsic protein
Loosely bound to the outside of the plasma membrane.
What is simple diffusion?
The movement of substances from an area of high concentration to an area of low concentration.
This happens because of the random motion of particles.
Doesn’t require any extra energy.
What are the rules for crossing the phospholipid bilayer?
If it is charged, polar or large it can not cross.
But water is polar and it can cross.
Why are amino acids and sugars not able to pass the bilayer?
Because they are polar and will be repelled by the fatty acid tails.
What is facilitated diffusion?
Molecules move from a high to low concentration. It is a passive process so it doesn’t require any extra energy. It diffuses with the aid of transport proteins.
What is active transport?
Molecules move from a low to high concentration. It is a active process, so it does require extra energy. It diffuses with the aid of transport proteins.
The extra energy is ATP
What is osmosis?
Osmosis is the diffusion of water from an area of low solute concentration (high water potential), to an area of high solute concentration ( low water potential) through a partially permeable membrane.
What is the difference between endocytosis and exocytosis?
Endocytosis is the hormone going into the cell.
Exocytosis = exists the cell.
What is phagocytosis?
It is a type of endocytosis.
Phagocytes are white blood cells that use phagocytosis to engulf and destroy pathogens.
- The pathogen interacts with the phagocyte receptors.
- Phagocyte engulfs the pathogen and becomes a phagosome.
- A lysosome breaks the pathogen down into proteins and other molecules.
Define magnification
Th degree to which something can be viewed larger than it is.
Define resolution
The shortest distance between two points on a specimen that can still be distinguished by the observer.
Features of a light microscope
Image beam: light
How is beam focused: glass lens
Max mag: x 10000
Max res: 100 nano meters
Can a live specimen be used: yes
Cost : cheaper
Staining required: yes
True colour seen: yes
Can image be viewed directly: yes
Features of electron microscope
Image beam : electrons
How is beam focused: magnets
Max mag: x1000000
Max res: 1 nano meter
Live specimen?: no
Cost : expensive
Staining of specimen: yes
Tue colour be seen: no
Can image be viewed directly: no
Equation for magnification
Magnification = image size divided by actual size.
What measurements do we use in microscopy?
We only millimetres.
There are 1000 nano meters (nm) in 1 micrometer
There are 1000 micrometers in 1 millimetre
Converting for microscopy
Nanometre Micrometer Millimetre
X1000 < X1000
%1000 > %1000
What is DNA short for?
What does it make?
Deoxyribonucleic acid.
It’s the code inside all of our cells and it makes proteins.