AS-LEVEL BIOLOGY SUMMARIZED NOTES
TABLE OF CONTENTS:
CHAPTER 1 Cell Structure Page 1
CHAPTER 2 Biological Molecules Page 5
CHAPTER 3 Enzymes Page 13
CHAPTER 4 Cell Membrane and Transport Page 17
CHAPTER 5 The Mitotic Cell Cycle Page 22
CHAPTER 6 Nucleic Acids and Protein Synthesis Page 26
CHAPTER 7 Transport in Plants Page 31
CHAPTER 8 Transport in Mammals Page 40
CHAPTER 9 Gas Exchange and Smoking Page 48
CHAPTER 10 Infectious Diseases Page 52
CHAPTER 11 Immunity Page 58
,AS-LEVEL BIOLOGY NOTES SUHAYB
CHAPTER 1 CELL STRUCTURE
PRESENCE OF ORGANELLES
animals both plants
centrosome surface membrane cell wall
centriole nucleus plasmodesmata
chromatin vacuole
DNA tonoplast
nucleolus chloroplast
cytoplasm chlorophyll
mitochondria
golgi
MAGNIFICATION & RESOLUTION
magnification the number of times an image is greater than the actual size of
the object
resolution the ability to distinguish between two objects very close together;
the higher the resolution, the greater the detail
magnification = image size / actual size
1 micrometer = 1000 millimetres
1 nanometer = 1000 micrometers
1
,AS-LEVEL BIOLOGY NOTES SUHAYB
TYPICAL FEATURES OF PROKARYOTES (BACTERIA)
always present sometimes present
cell wall flagellum (for locomotion)
surface membrane capsule (additional protection)
cytoplasm infold of cell membrane
circular DNA plasmid (small DNA circle)
ribosome pili (for attachment/sexual reproduction)
LIGHT VS. ELECTRON MICROSCOPY
no. feature light electron
1. source of radiation light electrons
2. wavelength 400nm 0.005nm
3. max. resolution 200nm 0.5nm
4. lenses glass condenser electromagnetic
5. specimen live/dead dead
6. stains coloured dyes heavy metals
7. image coloured black/white
STRUCTURES & FUNCTIONS OF ORGANELLES
name structure function
nucleus double membrane (nuclear pores allow control/exchange of
envelope); outer membrane substances for protein
continuous with ER; has nuclear synthesis; controls cell activities
pores
endoplasmic membrane extended as a small sacs called vesicles can
reticulum system of flattened sacs break off rough ER to join golgi
interconnected to form body; smooth ER makes lipids
reticulum; rough ER covered and steroids
with ribosomes; smooth ER
lacks ribosomes
ribosome has large and small units for protein synthesis
2
, AS-LEVEL BIOLOGY NOTES SUHAYB
golgi stack of flattened sacs; collects, processes, sorts
constantly being formed by ER; molecules from rough ER, ready
single membrane for transport to other parts of
cell/out of cell (secretion);
vesicles also used for
lysosomes
lysosomes spherical sacs; single breaks down unwanted
membrane; no internal structure; structures (old organelles);
contains digestive (hydrolytic) digests bacteria in WBC;
enzymes hydrolytic enzymes work in and
out of cell
mitochondria double membrane; inner aerobic respiration; lipid
membrane folded to form synthesis; produce ATP; porin
cristae; outer membrane forms aqueous channels; inner
contains porin membrane controls entrance of
ions/molecules into matrix
surface membrane extremely thin (7nm); double partially permeable; controls
membrane; 3 layers exchange between cell and
environment
microvilli finger-like extensions of the increase surface area of
surface membrane membrane for absorption
microtubules long, rigid, hollow tubes in make up cytoskeleton
cytoplasm; made up of tubulin
centrioles; hollow cylinder formed from a centrosome makes up spindle
centrosome ring of short microtubules found for cell division
in centromeres
chloroplast elongated shape; double photosynthesis; contains
membrane chlorophyll for green colour
cell wall rigid; contains cellulose fibres prevents cell from bursting;
gives cell definite shape
plasmodesmata fine strands of cytoplasm allow movement between cells;
outside cell wall link cells together
vacuole membrane-bound sacs within tonoplast controls exchange
cytoplasm between vacuole and
cytoplasm; contains fluid;
regulate osmotic properties of
cells
3
TABLE OF CONTENTS:
CHAPTER 1 Cell Structure Page 1
CHAPTER 2 Biological Molecules Page 5
CHAPTER 3 Enzymes Page 13
CHAPTER 4 Cell Membrane and Transport Page 17
CHAPTER 5 The Mitotic Cell Cycle Page 22
CHAPTER 6 Nucleic Acids and Protein Synthesis Page 26
CHAPTER 7 Transport in Plants Page 31
CHAPTER 8 Transport in Mammals Page 40
CHAPTER 9 Gas Exchange and Smoking Page 48
CHAPTER 10 Infectious Diseases Page 52
CHAPTER 11 Immunity Page 58
,AS-LEVEL BIOLOGY NOTES SUHAYB
CHAPTER 1 CELL STRUCTURE
PRESENCE OF ORGANELLES
animals both plants
centrosome surface membrane cell wall
centriole nucleus plasmodesmata
chromatin vacuole
DNA tonoplast
nucleolus chloroplast
cytoplasm chlorophyll
mitochondria
golgi
MAGNIFICATION & RESOLUTION
magnification the number of times an image is greater than the actual size of
the object
resolution the ability to distinguish between two objects very close together;
the higher the resolution, the greater the detail
magnification = image size / actual size
1 micrometer = 1000 millimetres
1 nanometer = 1000 micrometers
1
,AS-LEVEL BIOLOGY NOTES SUHAYB
TYPICAL FEATURES OF PROKARYOTES (BACTERIA)
always present sometimes present
cell wall flagellum (for locomotion)
surface membrane capsule (additional protection)
cytoplasm infold of cell membrane
circular DNA plasmid (small DNA circle)
ribosome pili (for attachment/sexual reproduction)
LIGHT VS. ELECTRON MICROSCOPY
no. feature light electron
1. source of radiation light electrons
2. wavelength 400nm 0.005nm
3. max. resolution 200nm 0.5nm
4. lenses glass condenser electromagnetic
5. specimen live/dead dead
6. stains coloured dyes heavy metals
7. image coloured black/white
STRUCTURES & FUNCTIONS OF ORGANELLES
name structure function
nucleus double membrane (nuclear pores allow control/exchange of
envelope); outer membrane substances for protein
continuous with ER; has nuclear synthesis; controls cell activities
pores
endoplasmic membrane extended as a small sacs called vesicles can
reticulum system of flattened sacs break off rough ER to join golgi
interconnected to form body; smooth ER makes lipids
reticulum; rough ER covered and steroids
with ribosomes; smooth ER
lacks ribosomes
ribosome has large and small units for protein synthesis
2
, AS-LEVEL BIOLOGY NOTES SUHAYB
golgi stack of flattened sacs; collects, processes, sorts
constantly being formed by ER; molecules from rough ER, ready
single membrane for transport to other parts of
cell/out of cell (secretion);
vesicles also used for
lysosomes
lysosomes spherical sacs; single breaks down unwanted
membrane; no internal structure; structures (old organelles);
contains digestive (hydrolytic) digests bacteria in WBC;
enzymes hydrolytic enzymes work in and
out of cell
mitochondria double membrane; inner aerobic respiration; lipid
membrane folded to form synthesis; produce ATP; porin
cristae; outer membrane forms aqueous channels; inner
contains porin membrane controls entrance of
ions/molecules into matrix
surface membrane extremely thin (7nm); double partially permeable; controls
membrane; 3 layers exchange between cell and
environment
microvilli finger-like extensions of the increase surface area of
surface membrane membrane for absorption
microtubules long, rigid, hollow tubes in make up cytoskeleton
cytoplasm; made up of tubulin
centrioles; hollow cylinder formed from a centrosome makes up spindle
centrosome ring of short microtubules found for cell division
in centromeres
chloroplast elongated shape; double photosynthesis; contains
membrane chlorophyll for green colour
cell wall rigid; contains cellulose fibres prevents cell from bursting;
gives cell definite shape
plasmodesmata fine strands of cytoplasm allow movement between cells;
outside cell wall link cells together
vacuole membrane-bound sacs within tonoplast controls exchange
cytoplasm between vacuole and
cytoplasm; contains fluid;
regulate osmotic properties of
cells
3
