2.1.1 Cell Structure

Question 1

Animal Cell

Answer 1

Plasma cell surface membrane, RER, SER, Golgi Apparatus, Nucleus, Nucleolus, Lysosome, Ribosome, Cytoplasm, Mitochondrion, Centriole.

Question 2

Plant Cell

Answer 2

Plasma cell surface membrane, RER, SER, Golgi Apparatus, Nucleus, Nucleolus, Lysosome, Ribosome, Cytoplasm, Mitochondrion, Cellulose cell wall, Permanent vacuole, Chloroplast.

Question 3

Prokaryotic Cell

Answer 3

Circular DNA, Plasmids, No nucleus, Peptidoglycan cell wall, Flagella in helix, No membrane bound organelles.

Question 4

Plasma cell surface membrane

Answer 4

Membrane on the surface of animal cells and inside plant and prokaryotic walls. Made of lipids and protein. Regulates the movement of substances in and out of the cell. Receptor molecules allow it to respond to chemicals.

Question 5

Cell Wall

Answer 5

Chitin in fungi, cellulose in plants, peptidoglycan in bacteria. Tensile strength and resisting osmotic stress.

Question 6

Nucleus

Answer 6

Nuclear envelope and pores, chromatin, nucleolus. Controls cells activities by controlling transcription as it contains the genes and instructions.

Question 7

Nucleolus

Answer 7

Makes ribosomes.

Question 8

Lysosome

Answer 8

Membrane bound organelle with digestive enzymes to break down or digest invading cells and worn out cellular components.

Question 9

Ribosome

Answer 9

Not membrane bound, two subunits, 70s in prokaryotic and 80s in eukaryotic. Protein synthesis.

Question 10

Rough Endoplasmic Reticulum

Answer 10

System of membrane enclosed fluid space with ribosomes on the surface. Folds and processes proteins made at the ribosomes.

Question 11

Smooth Endoplasmic Reticulum

Answer 11

System of membrane enclosed fluid space. Synthesises and processes lipids.

Question 12

Golgi Apparatus

Answer 12

Stack of flattened sacs often with branching vesicles. Packages and processes lipids and proteins and makes lysosomes.

Question 13

Vesicle

Answer 13

Membrane bound fluid filled sac. Transport in and out and around the cell.

Question 14

Mitochondrion

Answer 14

Double membrane, one is folded to form cristae, inside is the matrix which contains enzymes. Aerobic respiration for ATP.

Question 15

Chloroplast

Answer 15

Double membrane, membranes called thylakoid joined to make grana and linked by lamellae, fluid part called stroma. Site of photosynthesis in grana or stroma.

Question 16

Centriole

Answer 16

Made of microtubules Seperation of chromosomes in cell division.

Question 17

Cilia

Answer 17

Hair like structure, 9+2 microtubules. Move substances along the cell surface as they are external.

Question 18

Flagella

Answer 18

9+2 microtubules.
Microtubules contract to move the cell.

Question 19

Protein Production

Answer 19

1. Nucleus contains DNA and genes needed to transcribe MRNA using ribosomes
2. Translation occurs at the ribosomes/RER
3. Protein is modified and packaged into vesicles at the Golgi
4. Cytoskeleton moves vesicles to the cell surface membrane or organelles

Question 20

Cytoskeleton

Answer 20

Support organelles.
Strengthen cell and maintain shape.
Movement of materials in the cell such as chromosomes.
Whole cell movement by controlling cilia and flagella.

Question 21

Magnification

Answer 21

How many times bigger the image size is compared to the actual size of a specimen. IAM.

Question 22

Resolution

Answer 22

The ability to distinguish between two very close points.

Question 22

Light Microscopes

Answer 22

0.2 µm, X 1500 2D
Colour, live samples, light passes through sample.

Question 23

Laser Scanning Confocal Microscopes

Answer 23

3D, passes laser through.

Question 24

Transmission Electron Microscope

Answer 24

0.0002 µm, X 1,000,000 2D
Black and white, dead samples, electromagnets pass electrons and the more dense absorb more electrons.

Question 25

Scanning Electron Microscope

Answer 25

0.002, X 500,000, 3D
Black and white, dead samples, electrons knock off electrons which are collected in cathode ray tube.

Question 26

Staining

Answer 26

Shows contrast, makes organelles visible.
Methylene blue in light, heavy metal in electron.

Question 27

Mounts

Answer 27

Dry- Thin sample, place on slide using tweezers, place coverslip.

Wet- Water on slide, thin sample placed using tweezers, put coverslip upright and tilts and lower, place dye on one side.

Question 28

How to use a microscope

Answer 28

1. Clip the slide onto the stage
2. Lowest power objective lens (lowest magnification)
3. Coarse adjustment knob to bring stage to below objective lens
4. Look down the eyepiece and adjust coarse adjustment knob and then fine adjustment knob