Ocr A Biology 1.1.1 Cell Structure

Front 1

Resolution

Back 1

The degree to which it is possible for two items next to each other to be distinguished. The clarity of the image.

Front 2

Magnification

Back 2

The degree/extent to which the size of an image is enlarged.

Front 3

Transmission electron microscope

Back 3

Passes a beam of electrons through the specimen in a vacuum to produce a 2D image.

Front 4

Scanning electron microscope

Back 4

Passes a beam of electrons over the entire surface of the sample and provides a 3D image.

Front 5

Advantage of light microscope

Back 5

Maximum magnification *1500

resolution of 200nm

Can view large cells structures , living organisms and thin sections of larger plants and animals.

No training needed

Cheaper than electron microscope.

Front 6

Staining of a light microscope slide

Back 6

Staining, colour stains are chemicals that bind to other chemicals on or in the specimen allowing it to be seen.

Front 7

Disadvantages of a light microscope

Back 7

Not a very high resolving power

Can only see large organisms.

Front 8

Advantages of electron microscope

Back 8

Uses electromagnets to focus,

Maximum magnification of *500 000

Resolution 0.1 nm

Can view smaller structures which cannot be seen by the human eye or light microscope.

Produces detailed images of structures inside cells,

SEM produces 3D images

Front 9

Electron microscope staining

Back 9

Use of metal staining to bounce electrons off the specimen.

Front 10

Disadvantages of electron microscopes

Back 10

Samples must be placed in vacuum,

expensive

requires skill and training.

Front 11

Eukaryotic cells

Back 11

Any organism which contains a nucleus and any other membrane bound organelles.

Front 12

Nucleus

Back 12

Structure

Largest organelle structure, surrounded by nuclear envelope has nuclear pores and a double membrane.

Function

Protein synthesis, cell devision, growth and differentiation.

Found in

Animals and plants

Front 13

Nucleolus

Back 13

Structure

A non membrane bound organelle, formed around the nuclear organiser regions in the nucleus.

Function

Produces RNA, ribosomes, and is known for protein synthesis.

Found in

Animals and plants

Front 14

Rough Endoplasmic reticulum

Back 14

Structure

Consists of flattened membrane bound sacs, studded with ribosomes.

Function

Transports proteins made by attached ribosomes.

Found in

Animals and plants

Front 15

Smooth Endoplasmic reticulum

Back 15

Structure

Flattened membrane bound sacs, no ribosomes.

Function

Manufacturing of lipids (Fat enzymes)

Found in

Plant and animals

Front 16

Golgi apparatus

Back 16

Structure

A stack of membrane bound flattened sacs

Function

Receives proteins from rough E.R, may add sugar molecules to modify them. Then packages the modified proteins into vesicles for transport.

Found in

Plant and animals.

Front 17

Lysosomes

Back 17

Structure

Spherical sacs surrounded by a single membrane

Function

Contains powerful digestive enzymes.

Found in

Animals, and rarely but sometimes plants.

Front 18

Mitochondrion

Back 18

Structure

Spherical/sausage shaped. Has two membranes seperated by membrane fluid. Inner membrane folded to form cristae, has a centre called matrix.

Function

Atp production

Found in

Animal and plant

Front 19

Chloroplast

Back 19

Structure

Two membranes with fluid space, continuous inner membrane, thykaloids - flattened sacs.

Function

Site of photosynthesis in plants, forming carbohydrates from co2

Found in

Plants

Front 20

Ribosomes

Back 20

Structure

Tiny organelles some in cytoplasm some bound to Rough E.R, consists of two sub units.

Function

Protein synthesis in cell assembly lines where mRNA is used to assemble proteins from amino acids

Found in

Plant, animal and prokayrote

Front 21

Centrioles

Back 21

Structure

Small tubes of protein microtubules, non membrane bound and paired next to nucleus.

Function

Takes part in cell division, forms spindle fibres

Found in

Animals

Front 22

Flagellum

Back 22

Structure

Outer membrane bound a ring of 9 pairs of microtubules and a single pair in the middle. Microtubules slick over each other.

Function

Movement, uses ATP.

Found in

Prokaryote and Animals

Front 23

Cytoskeleton

Back 23

Structure

A cell consisting of a network of protein fibres giving the cell stability, protein fibres actin fillaments.

Function

Provides internal frame work preserving shape and holding organelles in place. Also movement and change in shape of cells with white blood cells.

Found in

Animal, plant and prokaryote.