Chap 1
1) why mitochondria diff shape?
-flexible
-cut at diff angle
-diff age
-some maybe dividing
2) importance of division of mitochondria
-for new cells/cell division
-cell growth
-replace old/damaged mito
3) why TEM but not SEM?
-show internal structure
-2D appearance
-high resolution
-very thin
4) why Golgi but not RER?
-NO 80s ribo
-not continuous w/ nuclear envelope
-golgi- sac have layered appearance
-swelling at end of sacs
>to tell from TEM: single membrane, flattened ascs
*5) why inner membrane less permeable than outer membrane of
mitochondria ?
-fewer transport proteins
-fewer unsaturated fatty acids, more packed
-higher proportion of cholesterol
6) double membrane
-nucleus, chloroplast, mitochondria
7) the structure that synthesises rRNA and combines it w/proteins
-nucleolus
*8) why aorta is an organ?
~bcuz more than one tissue
{endothelium, smooth muscle, elastin fibre, collagen fibres}
9) why sodium not passed by simple diffusion
-sodium are charged
-can’t pass through hydrophobic core
-needs transport proteins(by active transport against conc.
gradient )
*10) structure of mitochondria
-cristae
Cisternae
_
Golgi body
11). Common features (mitochondria& prokaryotes)
-circular DNA
-binary fission
-has 70s ribosome
12). Microvilli in small intestine
-increases surface area
-secretion of enzymes
13). Adv of plasmodesmata
-more rapid transport of substances between adjacent cells
14) role of lysosomes [3m]
-contains hydrolytic enzymes
-fuses with phagocytic vesicle
-eg: lysozyme, protease
15) State the function of the structure labelled F.
-separate hydrolytic enzymes from the rest of the cells
16) role of acid hydrolyses in lysosome.
-to catalyse (hydrolysis)
-to destroy the pathogen
-to break down dead cells
17).
RER- flattened sacs
SER- tubular, more irregular
18) Why very few mitochondria visible in electron micrograph?
-very thin section of cell
-mitochondria found in other section
19) why chloroplasts are seen only ard the periphery (edge) of
each plant cell?
-light absorption
Chap 2
1) Why no colour change when Benedict’s solution added to
sucrose& boil?
-no hydrolytic used, so sucrose does not hydrolysed to monomers
-sucrose will not reduce blue copper(II) ions to red copper(I) ions
Cut
(Cannot donate e)
cut
2) phospholipase (found in venom), breaks down phospholipid.
How bee venom destroys red blood cells?
-phospholipid bilayer are damaged.
-cell burst
-cell contents leak out
*3). Q: free enzyme-optimum pH 7 | immobilised-optimum pH4
Why diff optimum pH? [1m]
-free has greater exposure to hydrogen ions.
-immobilised enzyme has slightly altered active site.
4) Adv. of immobilised?
-more stable
-longer shelf life
-can be reused
-less time-consuming
5)
Feature
Antibody
Haemoglobin
Fibrous/globular
Globular
Globular
No.&name of polypeptide chain
2 heavy + 2 light
2 alpha + 2 beta
Type of bond (hold polypeptide tgt)
Disulfide
Ionic
6)
STATEMENT
ATP
CELLULOSE
HAEMOGLOBIN
PHOSPHOLIPID
Contain
phosphorus
Found in plants
Contains iron
Has a
structural role
7) Adv. of highly branched storage molecule.
-glucose can be stored quickly
-glucose can be mobilised quickly
-increased storage (more packed)
8) Why haemoglobin described as globular protein?
-spherical
-water soluble
-hydrophilic R-grps (outside)/ hydrophobic R-grps inside
9) Why described as a polymer?
-made of {monomers}
-joined by {bond}
-macromolecule by repeated monomers
10).
Effects of change in amino acid sequence of B-globin on the
structure and function of a haemoglobin molecule.
(glutamic > valine)
-change in tertiary& quaternary structure.
-(R-grp) glutamic acid polar, (R-grp) of valine non-polar.
-haemoglobin less soluble
-haemoglobin less efficient in binding
11) Role of haemoglobin in transport of carbon dioxide.
-haemoglobin combines w CO2
-CO2 reacts w NH2, to form carbominohaemoglobin
-1 polypeptide carries 1CO2.
-CO2 remains in region of low pCO2.
12) Why triglycerides cannot be described as polymers?
-not made up by repeating units
-not macromolecule
13)
Monomers
Polymers
Monosaccharides
Polysaccharide
Alpha- glucose
Alpha-globin
Alpha-glucose
Cellulose
Beta- glucose
Messenger RNA
Beta-glucose
Glycogen
Cellulose
Glycogen
14) STOP codon
-does not specify any amino acids
-has no complementary tRNA anticodon
Chap 3
2) higher activity of immobilised enzyme over the range.
-Immobilisation is protective
-shape of active sites less disrupted
-fewer bonds within immobilised enzyme break
2) lysosome hydrolyses B-1,4 glycosidic bonds found in bacterial
cell walls.
Q: Biological molecule which is substrate for lysozyme?
-peptidoglycan
3) How mRNA work out to correspond to the first five amino
acids may not be the same as the mRNA nucleotides sequences?
-more than one codon specifies for an amino acid
-64 codons and 20 amino acids
-genetic code is degenerate
-
-
stop
codon
does
not
specify
stop
codon
does
not
have
omitiwaon
any
amino
complementary
acid
tRNA
CHAP 4
1. How fatty acids exit the cell?
-facilitated diffusion (transport protein)
-high to low conc.
2. Why red blood cell cannot metabolise fatty acids?
-has no mitochondria
-impermeable to fatty acids
3. One way of immobilising an enzyme.
-In sodium alginate beads
-trapped in pores of silica gel
4. Thickness of cell membrane
-7nm
5.
O2/CO2- passive diffusion (movement from high conc. to low)
Glucose/amino acids/ mineral ions- facilitated diffusion (
channel
protein j
6. Capillary that is impermeable to substance (found in some area
of brain).
Q: State the difference of structure compared to the normal one.
-no pores in endothelium of capillary walls
7. How glucose crosses the cell membrane.
-facilitated diffusion using transport proteins
-specific binding site
-conformational change
8. Water can diffuse across membrane even though it is polar
-small enough
Facilitated diffusion (high to low)
i) ENERGY RELEASED BY respiration, no metabolic energy needed
ii) transport protein (channel& carrier)
Carrier
-specific binding
-conformational change to tertiary structure
Channel {central pore that line w hydrophilic amino acid }
-selective (only certain type hydrophilic substance can pass
through)
-some always open,
-some not always open (trigger by chemical binding, eg:
neurotransmitter)
*Even thought transport proteins are used, still diffuse
DOWN CONC.GRADIENT
Active transport (low to high con. gradient)
-ATP needed, lots of mito found
-carrier protein change shape