Energy and Metabolism Flashcards
(23 cards)
define metabolism?
the sum of all chemical reactions in which energy is made available and consumed in the body
what is energy used for in the body?
muscle contraction
movement of ions against conc. gradient
tissue building (biosynthesis)
waste disposal
heat generation/thermoregulation
when is delta G positive/negative?
positive - products more energy than substrate
negative - substrate more energy than products
what does exergonic and endergonic reactions mean?
exergonic - release energy in reactions
endergonic - require energy in reactions
what are the 3 molecular components of ATP?
phosphate groups, ribose and adenine
what happens in the first reaction of the TCA cycle?
acetyl CoA condenses with oxaloacetate to produce citrate
what are the 2 phases of the TCA cycle?
decarboxylating (citrate metabolised into succinyl CoA)
reductive (succinyl CoA to oxaloacetate)
what 2 molecules facilitate the movement of protons between radox centres?
coenzyme Q (from 1 -> 3)
cytochrome C (from 3 -> 4)
explain how much ATP is produced in the TCA cycle and oxidative phosphorylation
1 ATP produced by substrate-level phosphorylation
2.5 ATP for each NADH oxidised
1.5 for each FADH oxidised
what is the equation for anaerobic glycolysis?
glucose + 2ADP + 2Pi -> 2 lactate + 2 ATP
what is pyruvate dehydrogenase?
the process of pyruvate being turned into acetyl CoA
how can fatty acids be turned into ATP?
released from triglyceride stores in adipose tissue by lipase
transported to blood as an albumin complex and taken up by cells for oxidation
modified and enter mitochondria
beta-oxidation leading to ATP production
what is used to turn fatty acids into fatty acyl CoA?
CoA + acyl CoA synthetase
what is the transporter of fatty acids to different parts of the cell?
carnitine shuttle
how does beta oxidation degrade fatty acids and generates ATP?
cleaves the fatty acid backbone using CoA to gain 8 acetyl CoA molecules
acetyl CoA enters TCA cycle
NADH/FADH enters ETC
what are the 2 reactions used in protein metabolism?
transamination and deamination
how does transamination work?
takes amine group off amino acid and transfers it to keto acid
keto residue moves to amino acid in turn
how does deamination work?
amine group removed from amino acid + ammonia removal in liver
ammonia removal causes amino acid backbone removal which can convert into glucose
what do glucogenic and ketogenic amino acids form?
glucogenic - glucose (pyruvate/oxaloacetate)
ketogenic - fatty acids (acetyl CoA)
where does the body provide energy in times of no food?
protein and fat (triglyceride in adipose tissue)
what is basal energy expenditure?
the energy required to maintain basic functions when the person is lying down, relaxed and in a normal ambient temperature
what are the general guidelines for BMI results?
under 20 = underweight
20-25 = healthy
25-30 = overweight
over 30 = obese
what causes fatigue in terms of energy?
when energy expenditure exceeds energy consumption
