Summary 9700 AS Level Biology Syllabus Notes

, CHAPTER ONE
Define magnification
The amount of times an is greater than the actual size of the specimen
image


Define resolution

The ability to
distinguish between 2 separate points as separate



microscope provide detail than light microscope at the magnification
why can an electron more a same


1. Electron microscopes have a higher resolution

2. It is easier to distinguish between 2 separate points
3. Resolution for light microscopes is 200hm ,
but for EM it is 0.5 nm


4. Electron microscope uses electrons as a source of radiation ,
which has a shorter wavelength than light


Outline the structure & function of the cell membrane

1. Phospholipid bilayer
2.
Selectively permeable
3. Controls what enters & exits the cell

4. Separates cell from environment
5. Cell
recognition


Outline the structure & function of the nucleus

I. very dense
Large ,


2. Surrounded by a membrane with pores
3. Controls the cell's activities

4. Divides first during cell division

5. Contains nucleolus + chromatin



Outline the structure & function of ER
the
rough
1. Single membrane

2. Fluid -
filled sacs

3. Ribosomes attached
give rough appearance
4. Modify proteins


Outline the structure & function of the smooth ER

1.
Single membrane

2. Synthesizes steroids & hormones



Outline the structure & function of ribosomes
I. Made of 2 subunits :
large subunit , small subunit

2. Synthesize proteins


Outline the structure & function of the Golgi body
I. Flattened sacs of membrane

2. Single membraned

3. Package substances vesicles to be
into transported
4. Activates 1ˢᵗ amino
proteins by removing the acid methionine

5. Folds proteins

, Outline the structure & function of mitochondria Describe the general features of a rims

1. Double membrane 1. Parasitic

2. Site of aerobic respiration
2. Capsid
ATP 3. DNA/RNA nucleic acid core
3. Synthesizes
4. Contains TOS ribosomes & Circular DNA 4. Some have a phospholipid outer envelope

5.Non-cellular
structures


Outline the structure & function of lysosomes
1. Spherical vesicle

2. contains hydrolitic enzymes
3. Can cause programmed cell death

4.
Digest unwanted substances (worn out organelles)

Outline the structure & function of centricles

1 Found close to the nucleus at 90 each other

2.9 triplets of microtubules: 1 centricle

3.
Organise spindle fibres by forming a centrosome

4. microtubules
Organise

Outline the structure & function of microtubules

1. HOllOw tubes

2. Made from a tubulin & B tubulin
3. x tubulin tubulin form a dimer

4. Dimers from protofilaments which from the microtubule

S. Supports a to cells
gives shape
6.
Assembly controlled by MTOC


Outline the structure & function of chloroplasts
1. Double membrane

2. Contain TOS ribosomes

3. Contain small circular DNA

4. Site of photosynthesis


Outline structure & function of the cell wall

1.
fully permeable
2. Contains cellulose

3. Gives definite shape & prevents bursting


Outline the structure I function of the plasmodesmata
1 strands of cytoplasm that pass through pores
2. Allow for cell to cell
signaling/communication
3. Make up the symplastic pathway


Describe how prokamotes differ from eukaryotes
1. TOS ribosomes 8. Unicellular

2. Circular DNA 9.
1-5mm in diameter
3. No membrane bound organelles
4. Plasmids

3.
Peptidoglycan cell walls

6. DNA is naked, not associated with histone proteins
not
7. DNA membrane bound