Unit 3 Metabolism Part 1 Flashcards
Metabolism
the sum of all chemical reactions in the body
what are the two types of metabolism
catabolism and anabolism
catabolism
BREAKdown
- EXergonic
what does exergonic mean
release energy
anabolism
BUILDing
- ENDergonic
what does endergonic mean
consumes energy
what is the 1st law of thermodynamics
the law of conservation of energy
law of conservation of energy
energy can be neither created or destroyed, only converted
ATP
useful form of chemical energy in our bodies
What are the two types of energy transfer
oxidation and reduction
oxidation
involves the REMOVAL of electrons from an atom or molecule
reduction
involves the addition of electrons to an atom or molecule
what is the main energy transfer rule
oxidation and reduction must ALWAYS be COUPLED
Redox reactions
if one is reduced the other is oxidized
what is another term for oxidation
DEHYDROGENATION
What is another word for reduction
HYDROGENATION
What are the main macronutrients
carbohydrates, lipids and proteins
glycolysis
glucose breakdown to produce ATP
What type of metabolism reaction does glycolysis experience
CATABOLIC
gluconeogenesis
formation of glucose from lipid or protein
what type of metabolic reaction does gluconeogenesis experience?
ANABOLIC
glycogenolysis
breakdown of glycogen into glucose
what type of metabolic reaction does glycogenolysis experience?
CATABOLIC
glycogenesis
synthesis of glycogen from glucose
what type of metabolic reaction does glycogenesis experience?
ANABOLIC
Is glycolysis aerobis or anaerobic?
both
aerobic
with oxygen
anaerobic
without oxygen
Mitochondria
needs oxygen
- krebs and etc
- sometimes glycolysis
cytosol
does not need oxygen
- glycolysis
Glycolysis Characteristics
- fast
- w/ or w/o oxygen
Krebs Cycle Characteristics
- slow
- high ATP yield
- Aerobic
ETC Characteristics
- slow
- high ATP yield
- Aerobic
What are simple sugars
monosaccharides and disaccharides
Examples of monosaccharides
- GLUCOSE
- FRUCTOSE
- GALACTOSE
Examples of disaccharides
- maltose = glucose + glucose
- sucrose = glucose + fructose
- lactose = glucose + galactose
examples of POLYSACCHARIDES
- glycogen
- cellulose
- starch
Glycogen
main polysaccharide in the body
What is known as the storage form of glucose
glycogen
where is glycogen stored
liver and skeletal muscles
how does glucose enter the cell
facilitated diffusion performed by GluT molecules
what increases the presence of GluT4 transporters in the plasma membrane for facilitated diffusion of glucose?
INSULIN – this helps increase the rate of diffusion
Cellular respiration
OXIDATION of glucose to make ATP
What are the 4 sets of reactions in cellular respiration
- Glycolysis
- Formation of Acetyl CoA
- Kreb’s Cycle reactions
- ETC reactions
Dehydration Synthesis
REMOVE water
monosaccharides -> disaccharide
Hydrolysis
ADD water
disaccharide -> monosaccharides
how many carbons are in one glucose at the start of glycolysis
6 carbon molecule split into 2 3 carbon molecules of pyruvic acid
what are the 3 phases of glycolysis
- sugar activation
- sugar cleavage
- sugar oxidation and formation of ATP
What are the characteristics of glycolysis
- rapid rate
- low amount of ATP produced
- anaerobic in cytosol or aerobic in mitochondria
What stimulates PFK
- INCREASE IN adp, amp, pi and decreased pH
- DECREASE IN available oxygen
what happens when PFK is stimulated
the breakdown of glucose is increased and that means that the rate of glycolysis increased as well
what will INHIBIT PFK, thus decreasing the rate of glycolysis
- increase in glucose - 6 - phosphate
- lots of ATP and citrate
what are the key enzymes of glycolysis
hexokinase, phosphofructokinase, lactate dehydrogenase, pyruvate dehydrogenase
Hexokinase
conversion of glucose to glucose 6 phosphate (step 1) in glycolysis
Phosphofructokinase
(PFK) regulates the rate of glycolysis
Lactate dehydrogenase
(LDH) converts pyruvate to lactate (glycolysis)
pyruvate dehydrogenase
converts pyruvate to Acetyl CoA (Krebs)
characteristics of the krebs cycle
- slow
- high atp yield
- aerobic in mitochondria
what is the ETC
a series of electron carriers
what are some characteristics of the ETC
- SLOW
- greatest ATP yield
- aerobic in mitochondria
Matrix
folds within the mitochondria
CHEMIOSMOSIS
pumping of Hydrogen ions
describe etc
- each carrier is reduced as it gains electrons and oxidized as they lose them
EXERGONIC reactions release energy used in the form of ATP
How do channels open in the ETC
gradients are built when ions are all pushed to one side. this build allows hydrogen ions to rush into the inter membrane space and then to the ATP synthase
what is the goal of the ETC
couple energy stored in electron acceptors to a proton gradient that drives ATP synthesis
Inner mitochondrial membrane in etc
contains a series of channels and the ATP synthase
what are the two parts of oxidative phosphorylation
- etc
- chemiosmosis
what lives in the mitochondrial matrix
H+
what goes through ETC first
NADH from krebs
- gives up its protons and electrons to complex 1 causing it to be super charged to form NAD+. gives complex one the energy to pump H+ into the inter membrane space. and its electron is given from complex 1 to CoQ. accumulation of h+ on other side, proton gradient forms in IMS.
FADH2
coming from krebs, FAHD2 approaches complex 2 and gives up electrons and becomes FAD. complex 2 cannot however pump, so its electron goes from complex 2 to CoQ.
CoQ
common electron acceptor for complex one and complex 2 in the ETC. passes electrons to complex 3 and causes enough potential to pump H+ through complex 3 to intermembrane space. complex 3 passes electrons to CytC then to complex 4 and pumps protons to IMS
final electron acceptor
oxygen
- splits into two o ions
- creates two water molecules in the mitochondrial matrix
ATP synthase
uses built up proton gradient to generate large amounts of ATP
ADP wants to turn into ATP…
ATP synthase uses protons from IMS and flows down gradient and go back to matrix and catalyses the conversion of ADP to ATP … PROCESS CONTINUES
What stimulates glycogenesis
INSULIN
where does insulin store glucose
stores it as glycogen in the liver and skeletal muscle
what enzyme is associated with glycogenesis
hexokinase
what stimulates glycogenolysis
glucagon and epinephrine (increased blood sugar results)
what enzymes are associated with glycogenolysis
phosphatase and phosphorylase
what stimulates gluconeogenesis
cortisol - high stress hormone
glucagon - when blood sugar is low
what hormone inhibits gluconeogenesis
insulin
