escribe the importance of ATP in cells, giving examples of processes in which it is used.
It provides energy. Examples: muscle contraction, protein synthesis, DNA replication, cell
movement,
and
active transport.
ATP is described as having a
universal role as the energy currency in all living organisms. Explain why
it is described in this way
.
Energy is release
d when ATP is hydrolysed. ATP
is easily hydrolysed. Th
e energy it releases is used in
processes/ reactions. It has a rapid turnover, and
it links catabolic and anabolic reactions. It is found in
m
ost cells/ all organisms. ATP
is
water
soluble
,
so it is easily moved (within the cell).
It links between
energy yielding and energy requiring reactions.
ATP is also produced from a variety of rea
ctions.
State prec
ise
places where ATP is synthesised in cells.
ETC/ inner mitochondrial membrane/ crista/ stalked particles, grana/ thylakoids/ inner
chloropla
st
membrane, cytoplasm/ cytosol,
mitochondrial matrix.
Explain the role of ATP in active transp
ort of ions and in named anabolic reactions.
ATP provides energy for active transport, during movement of an ion against its
concentration gradient.
A carrier/ transport protein (in the membra
ne) binds to the (specific) ion
, and the protein changes
shape.
An anabolic reaction is the synthesis of complex substances from simpler ones. Starch/
cellulose/
glycogen is synthesised from monosaccharides/ named monosaccharides/ named sugar,
ATP provides
energy for the formation of glycosidic bonds. For a lipid/ tri
glyceride being synthesised from fatty acids
and glycerol, ATP provides energy for the formation of ester bonds. For polypeptides/
proteins,
synthesised from amino acids, ATP provides energy for the formation of peptide bonds.
State precisely where these t
wo processes occur in a cell:

Substrate level phosphorylation:
In the cytoplasm (in glycolysis), and the matrix of the
mitochondria (in Krebs cycle).

Oxidative phosphorylation:
In the i
nner m
embrane of mitochondria/cristae.
Compare the relative amounts of
ATP produced by the SLP and oxidative phosphorylation when a
molecule of glucose is completely oxidised.
Oxidative phosphorylation produces more ATP molecules than substrate level
phosphorylation, 32/34
vs. 4/6 per glucose.