Lipid and Amino Acid Metabolism Flashcards
why do we need energy?
Synthesis & maintenance of their own structures.
-in growth, or in repair after injury.
Performance of mechanical work.
-muscle contraction
Active transport of substances into & out of cells
-import of food molecules from gut into cells – “digestion”
where is the energy derived for theses processes
light- phototrophs
chemicals (food)- chemotrophs
Processes that release energy are what?
favoured
Processes that require energy are what?
not favoured
why is energy required
overcome the forces preventing movement of the body (gravity, air resistance, friction etc).
how is energy released?
energy release from Glucose
what does food usually contain?
carbon-containing compounds
the oxidiaton of glucose results in?
Breakdown of “carbon skeleton” of glucose molecule
Combination of carbons with oxygen to form carbon dioxide.
Formation of water from remaining hydrogens and oxygens.
the breakdown of glucose produces how much energy?
16000 J per gram of glucose
energy derived from food is converted into what?
ATP.
describe atp
principal donor of energy to Biological Systems
energy-rich molecule due to its 3 phosphate groups – ‘triphosphate
why is atp described as “cash in hand”
readily ‘top-upable’; ATP & its lower-energy form ADP are readily interconvertible; reaction catalysed by Adenylate Kinase
what is the atp and adp cycle
biological process that cells use to store and release energy.
why is the adp and adp cycle continous?
cells constantly use and regenerate ATP. Enzymes called ATPases are involved in the hydrolysis of ATP, and other enzymes like ATP synthase help in the synthesis of ATP.
describe metabolsim
catabolism and anabolsim
what is substrate level phosphorylation
Direct Transfer of phosphate gp from metabolites to ADP - producing ATP.
the generation of atp in glycolysis is what?
anerboic
what is Oxidative phosphorylation
atp formed INDIRECTLY from oxidation of carbon atoms in fuel molecules (carbohydrate, fat, amino acids)
what % of atp is formed in oxidative phosphorylation
90%
what is the main purpose of mitochondria
Organelles that generate ATP (via oxidative phosphorylation) for cellular use
where is mitchondira mainly present
larger numbers where lots of energy is required (eg. cardiac muscle cells, sperm flagella)
describe the structure of mitchondria
Surrounded by a double-membrane system
Outer membrane.
Inner membrane.
Intermembrane space
Interior (matrix)
what is the role of mitochondrial reactions in metabolsim
Oxidative decarboxylation
Oxidative decarboxylation ?
oxidation + loss of C atoms
where does the etc get energy release from?
energy release from oxidation to energy-requiring H+ pumping across inner membrane into intermembrane space
how does atp synthase produce energy in oxidiative phosphyrlation?
H+ escape across inner membrane to energy-requiring ATP synth.
[3x H+ synth of 1x ATP]
because of intergrated metabolsim what can cells also depend on?
other carbohydrates, including glycogen
fats
proteins/amino acids
what is a ‘junction point’
molecules or metabolic stages that play a pivotal role in the regulation of metabolic pathways
