cell biology miss bilingly

What does a nucleus consist of?

Nucleolus, nucleus envelope, chromosomes

What is nucleoli and function

To synthesis rRNA and make ribosomes

What does dna usually consist as in the nucleus?

Chromatin

What is endoplasmic reticulum?

A series of membrane folds that connect to the nuclear envelope

What are the folded membranes called

Cisternae

What does RER have and its function?

RER has ribasomes on cisternae and Carries out protein synthesis and the RER processes proteins produced by those ribasomes

What does the SER do?

Synthesis and store lipids and carbohydrates

What does the Golgi have?

Folded membranes making cisternae then vesicles Produced

What is the Golgi considered as?

The processing and packaging centre

How does RER and Golgi connect to make vesicles?

RER processes proteins and transports them to the Golgi where is is packaged and modified into vesicles

What does the Golgi do to the protein when it recieves it from the RER?

It add carbohydrates to from a glycoprotein

What is another type of vesicle?

Golgi produces vesicle containing hydrolytic enzymes which become a lysosome

Where does the enzymes in a lysosome need to be kept?

Seperately from the rest of the cell by a membrane

What are the enzymes used for?

Digesting invading cells

What are also digested by the enzymes?

Worn out or dead organelles for reuse of materials

What does mitochondria have?

Double membrane and the inner membrane is called cristae

What substance is inside the mitochondria? What is the name?

Fluid Called the matrix

What is the inner membrane coated with?

Enzymes to catalyse aerobic respiration to make ATP

What is ATP?

The molecule that provides energy for cellular processes

What is the form of DNA in mitochondria?

Loop

What are ribasomes made up of?

Protiens and rRNA

Where are large ribasomes found?

In eukaryotic cells

Where are small ribasomes found?

In prokaryotic cells, mitochondria and chloroplast

Function of a ribasome?

Protein synthesis

What is vacuole filled with and surrounded by?

Filled with fluid and surrounded by membrane called tonoplast

Function of vacuole?

Keep cell turgid

What does vacuole temporarily store?

Sugars and amino acids

What does chloroplast have that surrounds it?

A double membrane

What does chloroplast contain? 2 things

Thylakoid which is folded membranes and fluid called Stroma

What does the stroma contain?

Enzymes for photosynthesis

They have stacks of ……… called ……

Thylakoid, grana

Where are cell walls found?

In plant and fungi cells

What is cell wall used for?

Structural strength

What does plasma membrane control?

What can exit and enter the cell

What are dotted along the cell membrane? And for what

Protiens to recognise what should and shouldn’t enter the cell

What is needed in between the cell membranes?

Cholsterterol to keep it together

What is the liquid part of ythe cytoplasm called?

Cytosol

What is the cell wall made out of?

Cellulose

What is cellulose made out of?

Polysaccharide

What do eukaryotes have that prokaryotes dont?

A nucleus

Membrane bound organelles like

RER, SER

Golgi

Mitochondria

Chloroplast

80S ribosomes

Lysosome

What do prokaryotes have that eukaryotes don’t

Loop of DNA

Plasmid

70S ribosomes

Slime capsule

Flagellum

What are the function of plasmids

Additional DNA. The cell can live wihtout it

What are the types of ribosomes?

70S- prokaryotic

80S- eukaryotic

What does the nucleus consist of

Nuclear envelope

Nuclear pores

Nucleoplasm

Chromosomes

Nucleolus

What is the nucleoplasm?

Jelly like material that bulks the nucleus

Which eukaryotes have call walls?

Plants and fungi

What do plant cell walls contain?

Microfibrils of cellulose

What does fungi cell walls contain?

Chitin which is a nitrogen containing polysaccharide

What does the cell walls contain in prokaryotes?

Murien

What does the slime capsule contain and do in prokaryotes?

Proteins and keeps the cell from desicating and protects the cell from the hosts immune system

What is the size of a prokaryote and eukaryote

Pro- 0.1-0.5 micrometers

Euk- 10-100 micrometers

Explain binary fission for prokaryotes (4)

• DNA replicates and plasmids replicate many times

• Cell elongates and DNA moves to opposite ends of the cell

• Cytoplasm divides and new cell wall forms

• Daughter cells with identical DNA loops but different number of plasmid copies

Viruses are ………..

Non living

Why are they non living

They cannot perform metabolism functions without a host

What is the size of a virus

20-300 nm

What do viruses consist if

Nucleic acid like DNA or RNA

What is the nucleic acid enclosed within

Protein layer called capsid Or lipid envelope

What do the capsids have

Attachment proteins

Viruses are a……..

Acellular

Who discovered cells?

Robert Hooke

What does magnification mean?

How many times larger an image is comapred to the actual object

What is resolution?

The ability to distinguish between two points that are close together as seperaste points

What determines the resolution in a light microscope?

The wavelength of light

What determines the resolution of an electron microscope ?

The wavelength of beam of electrons

how do increase magnification?

Increase power objective lens

What is the maximum resolution and maximum magnification for light microscope?

Reolution- 200 nm

Magnification- 2000x

What is the lens used for light microscope?

Glass

What specimen can u see in light microscope?

Alive

Is stain necessary for a light microscope?

No but helpful

What is the image formed for the light microscope?

Inverted

Coloured

2D

Why do light microscopes have a poor resolution?

Long wavelength of light

What is not visible in light micrscope?

Small organelles

What is the maximum resolution and magnification for transmission electron microscope?

Resolution- 0.1 nm

Magnification- 500 000x

What is the lens used for TEM?

Electromagnet

What is the specimen for TEM? And why

Dead Because it is placed in a vacuum which kill the cell

What is the stain used in TEM? Why

Heavy metal Because they scatter electrons well creating contrast so structures can be seen more clearly

What is the image formed in TEM?

2D

The colouring of the images are…..

Black ans white

How are the specimens cut in a TEM?

Very thinly

What does it mean when dome areas of the image formed are darker than other?

More electrons have been absorbed

Why does the specimen have to be very thin

For the electron the pass through to form image

What is the difference in electron application in SEM?

Electrons scan the surface and electrons are scattered From the surface in different ways

Maximum resolution and magnification for SEM?

Resolution- 10 nm

Magnification- 100 000x

What is the lens for SEM?

Electromagnet

What do they put on the specimen in SEM?

Coated with thin layer of heavy metal

What is the image formed for SEM?

3D

What is cell fractionation used for?

Cell is broken up ans different organelles are seperated out

What are the organelles seperated according to?

Density

What does state of tghe solution have to be in before the cell is broken up?

• cold

• Isotonic

• Bufffered

Why does it have to be cold?

To stop enzyme activity so they wont digest the organelles

Why isotonic?

To keep the water potential the same so the cell wont shrink or burst due to osmosis

Why buffered?

Keep ph the same so that’s enzymes dont denature

Now state the steps of cell fractionation? Explain each step

• homogenation and filtering- cell Is cut open to release organelles and filtered to remove any debris like large cell membrane

• Ultracenttrifugation- spun at high speed and heaviest/dense ones will sink to the bottom. As speed increases the lighter ones will slowly follow

What is the order of separation of organelles?

• nuclei

• Mitochondria and chloroplast

• Ribosomes

What is centrifugation at different speeds called?

Differential centrifugation

Equation for magnification

Image size over actual size

When using a light microscope, what can you use to measure the size of objects?

Eye piece graticule

Where is the eyepiece graticule placed?

In the eyepiece of the microscope

Why can you not use the eyepiece graticule drisectly to measure the size of an object?

Because each objective lens will magnify to a different degree

So what must you do to the eyepiece graticule?

Calibrate it with a stage micrometer