Metabolism Flashcards
Oxidoreductase
oxidation reduction
includes: oxidases, reductases, dehydrogenases
transferases
functional group is transferred
includes: kinase, phosphorylase
hydrolase
cleave of one molecule into two molecules using water
ex: phosphatase, protease, lipases, nucleases
lyase
break bonds without the removal of water; usually results in a double bond
ex: decarboxylase, synthase, aldolase
isomerase
functional group movement within a molecule
ex: mutase
ligases
joining two molecules to form one via bond formation and ATP hydrolysis
ex: carboxylase, synthetase
condensation
releases water to connect two molecules to form one
fatty acid synthesis
occurs in the cytosol
combines malanoyl CoA + acetyl CoA and oxidized NADPH –> NADP+ to create palmitate
creates a long chain of fatty acids stuck together in the cytosol
uses acyl carrier protein
uses ATP –> ADP + Pi
- condensation
- reduction (NADPH –> NADP+)
- dehydration (remove H2O)
- reduction (NADPH –> NADP+)
anabolic reactions
build complex molecules from less complex things
requires energy, reducing power, and sufficient precursor molecules to build new macromolecules
pentose phosphate pathway
oxidative phase: produces NADPH
non-oxidative phase: uses ribulose 5 phosphate to go through a series of steps which can create DNA/RNA
- also another way to oxidize glucose. Can end up with glyceraldehyde 3 phosphate
What is the rate limiting step for the PPP?
glucose-6-phosphate dehydrogenase
activated by NADP+ and inhibited by NADPH and insulin
what is different about long fatty acid chains than medium and small chains for beta-oxidation?
small and medium fatty acid changes can diffuse through the inner and outer membrane to enter mitochondria
long fatty acid chain requires to be transported into the mitochondria using carnitine to transfer through tranferase
carnitine palmitoyltransferase (CPTI) does what?
converts fatty acyl CoA to fatty acylcarnitine
rate limiting step
How does long chain fatty acid move from cytosol to inner membrane space?
acyl synthetase converts fatty acid into fatty acyl CoA which can diffuse through layer
what does translocase do?
transfers fatty acylcarnitine from IM space to matrix
what does carnitine palmitoyltransferase (CPTII) do?
CPTII converts fatty acylcarnitine back into fatty acyl CoA to begin beta oxidation because is now located in matrix
How does acetyl CoA move out of the matrix to the cytosol for fatty acid synthesis?
acetyl CoA + oxaloacetate ==> citrate which can diffuse between the mitochondrial layers and will revert back to acetyl CoA + oxaloacetate once back in cytosol
what does pyruvate dehydrogenase complex require to make acetyl CoA
CoA, TPP, lipoic acid, and NAD+
insulin
released from beta cells of pancreas islets of Langerhans in response to high blood glucose levels
increases: glycogen synthesis lipogenesis protein synthesis glycolysis
decreases: glycogenolysis gluconeogenesis lipolysis ketogenesis
activates pyruvate dehydrogenase complex
glucagon
released from alpha cells to increase blood glucose levels
acetyl CoA carboxylase
conversion of acetyl CoA –> malonyl CoA with the addition of CO2 using ATP
- required for fatty acid synthesis
hormone sensitive lipase
helps triacylglycerides break down into fatty acids and glycerol
activated by glucagon and inhibited by insulin
transamination
transfer of amine group
alpha amino acid transfers amine to alpha ketoglutarate to become glutamate. alpha amino acid turns into alpha keto acid
glutamate will donate NH3+ to be combined with CO2 to enter urea cycle, and will revert back to alpha ketoglutarate
protein catabolism
breakdown of polypeptide chains and proteins into individual amino acids to produce ATP, glucose, or new proteins
glucogenic
amino acids are converted to pyruvate or CAC intermediates –> convert to glucose
ketogenic
amino acids are converted directly to acetyl CoA which can enter CAC or become ketone bodies
product inhibition
type of negative feedback in which the end product of a reaction pathway decreases its own production by binding to enzyme or regulatory protein needed in an earlier step
constitutional isomers
same molecular formula with different bonding types at at least one position
D glucose vs D fructose
D glucose is an aldose and D fructose is a ketose
epimers
differ at only one stereocenter
D-glucose and D-mannose only different at one position
anomers
differ at the anomeric carbon
enantiomers
differ at every single stereocenter
awkward turtle where they fit on top of each other but stick out because opposite orientation
D-mannose and L-mannose
glycosidic bonds
bonds between anomeric carbons of carbohydrates and any other biological molecule
must have a free anomeric carbon so cannot be sucrose
sucrose
cannot form glycosidic bonds because are linked by anomeric carbons
glucose + fructose
lactose
disaccharide
glucose + galactose
maltose
disaccharide
glucose + glucose
monosaccharides
glucose, galactose, fructose, ribose
have a free anomeric carbon which can be linked via glycosidic bonds –> reducing ring because donate hydrogens and become oxidized when form bond
What is the most common nonreducing sugar?
sucrose
cannot form glycosidic bonds because does not have a free anomeric carbon
What pathways can fructose 6 phosphate enter?
glycolysis and become fructose 1,6 biphosphate
gluconeogenesis and become glucose 6 phosphate
OR
combine with glyceraldehyde 3 phosphate and enter PPP to become ribose 5 phosphate
glycogen is linked horizontally via
alpha 1-4 subunits
glycogen is branched with connections via
alpha 1-6 subunits, about every 10 glucose molecules
glycogen branching enzyme
glycogenolysis
breakdown of glycogen
occurs when low blood glucose
glycogen becomes glucose 1 phosphate + glycogen(n-1) through glycogen phsophorylase
glycogen phosphorylase
breaks down glycogen into glucose 1 phosphate + glycogen (n-1)
breaks bond between 2 adjacent glucose molecules in a glycogen chain by phosphorolysis (addition of phosphate)
ubiquitination
ATP dependent process that adds a target molecules (ubiquitin) to a target protein which will signal the protein to enter the proteosome to be cleaved into small peptides via proteolysis
hydroxylated
adding an OH group
proteins that are ubiquitously expressed
have consistent concentration levels across all cell/tissue types
used as loading controls to show that all lanes in a gel have the same amount of sample loaded into them
Cori cycle
process of carrying lactate from the muscle to the liver and moving regenerated glucose from the liver to them muscles
it connects gluconeogenesis and glycolysis
In a 16 carbon fatty acid, how many ADP and NADP+ molecules will be produced?
7 ADP and 14 NADP+
need to make malonyl CoA from acetyl CoA 7 times and then will need to reduce the bonds using NADPH –> NADP+ 14 times
Can a furanose or pyranose form a phosphodiester bond?
Only furanose can form a phosphodiester bond because it needs a free 5’ OH group that can grab onto the phosphate
pyranose has that 5’ O group inbedded into the cyclical structure and would take on an unstable positive charge if it bound to a phosphate
nucleotide
contains a nitrogenous base, ribose, and a triphosphate group linked to the 5’ carbon of ribose
ribose is a 5 carbon sugar (pentose) and must adopt the furanose form to be incorporated into the nucleotide triphosphates
How many electrons does NADH hold?
NADH can hold up to 2 electrons
so can FADH2, but it can only pass 1 electron at a time. Same with ubiquinol.
cytochrome C can only hold and transfer one electron at a time
How many electrons is required to turn O2 into water?
4 electrons
so 2 NADH molecules are needed to pass their electrons through the ETC
What will deaminated alanine become?
deamination means that the NH3 group comes off
this will turn alanine into pyruvate
Citrate shuttle
pyruvate and citrate can cross over between cytoplasm and mitochondria
they also both can convert into oxaloacetate which means that:
citrate –> oxaloacetate will remove acetyl CoA into the cytoplasm
oxaloacetate –> citrate will hide acetyl CoA within citrate so that it can be transported into the cytosol and can participate in fatty acid synthesis.
What happens when triacylglycerol is needed?
It is released from adipocytes when there is low energy and we have run out of glucose
3 fatty acids and 1 glycerol will be released
What happens to the fatty acids that are released from a triglyceride?
They will undergo beta oxidation to be broken down into acetyl CoA which will enter the CAC
What happens to the glycerol backbone when it is released from triacylglycerol?
It will be converted:
glycerol –(glycerol kinase)–> glycerol 3 phosphate –(glycerol phosphate dehydrogenase)–> DHAP –(triose phosphate isomerase)–>glycerol 3 phosphate which can enter glycolysis or gluconeogenesis depending on the need by the body
What is required for long chain fatty acids to move into the mitochondria?
the long chain fatty acid must be modified
- acyl CoA synthetase adds on a CoA to form acyl CoA but this reaction is thermodynamically unfavorable and requires ATP –> ADP hydrolysis to proceed
- acyl CoA migrates to intermembrane space where reacts with carnitine to form acylcarnitine
- acylcarnitine translocase will carry acylcarnitine into mitochondrial matrix where it is converted back to acyl CoA and carnitine
acyl CoA is then digested by Beta oxidation and carnitine is transported back to the intermembrane space where it will be able to pick up another long chain fatty acid.
Citrate shuttle
pyruvate and citrate can cross over between cytoplasm and mitochondria
they also both can convert into oxaloacetate which means that:
citrate –> oxaloacetate will remove acetyl CoA into the cytoplasm
oxaloacetate –> citrate will hide acetyl CoA within citrate so that it can be transported into the cytosol and can participate in fatty acid synthase.
