TEST 4 Flashcards
fatty acid degradation properties
- Occurs in mitochondria
- Produces FADH 2 and NADH
- Produces acetyl CoA
fatty acid synthesis properties
- Occurs in cytoplasm
- Uses NADPH
- Uses acetyl CoA
triglyceride degradation
1) hydrolysis of tryglycerides to get fatty acids
2) activation and transport of fatty acids into mitochondria
3) Beta oxidation of fatty acids to produce acyl CoA
lipids are stored as what
mostly as tryglycerides
what does lipase do
oxidizes H20 to 02, adds hydrogen to equation
converts triglycerides to glycerol and fatty acids
liver cell degradation of triglycerols
glycolysis and gluconeogenesis
all other tissues of degradation of triglycerols
fatty acid oxidation, enters TCA cycle
transport of fatty acids into mitochondria
requires 2 ATP & carnitine
hydrolysis of PPi drives reaction of fatty acid to acyl adenylate to acyl CoA
B oxidation of fatty acids to produce acetyl CoA steps
1) oxidation of Acyl CoA by FAD+, FAD+ gets reduced
2) Hydration (addition of H20 to CoA molecule)
3) oxidiation of CoA molecule by NAD+, NAD+ gets reduced
4) Thiolysis of CoA (cleaving of molecule CoA group from molecule to make Acetyl CoA)
Step 1 of B Oxidation
oxidiation of Acyl Coa by FAD+
Step 2 of B Oxidation
Hydration
Step 3 of B Oxidation
Oxidation by NAD+
Step 4 of B Oxidation
Thiolysis of CoA to Acetyl CoA
How many carbons get removed per step in B Oxidation
2 carbons are removed per step
How many FADH2 and NADH2 are created per round B Oxidation
1 NADH
1 FADH2
How many FADH and NADH2 are created from a C16 saturated fatty acid?
7 NADH
7 FADH2
8 acetyl CoA
how to change unsaturated to saturated fatty acid
-isomerase shifts position of double bond
-no production of FADH 2 during
first round of β-oxidation if unsaturated
what occurs with a odd chain of fatty acids?
-final round of B oxidation produces acetyl CoA as normal,
-once it hits the end, it creates 3 carbon propionyl CoA which is then turned into Succinyl CoA for use in TCA cycle
ketone bodies
another source of fuel derived from fats
ketone bodies can be formed how
can be formed from acetyl CoA
properties of ketone bodies
-doesnt generate as much ATP
-water soluble easily transported
-can be used as fuel for brain as last resort
fatty acid synthesis transport from mitochondria to cytoplasm
1) Acetyl-CoA transferred from
mitochondria to cytoplasm.
2) Acetyl-CoA activated to malonyl CoA.
3) Reaction intermediates attached to thiol
groups on fatty acid synthase
acetyl CoA to malonyl CoA
step 2 of how fatty acid chains are created
requires ATP and CO2
attaches CO2 to acetyl CoA
fatty acid synthesis steps
- Condensation – Loss of CO2
- Reduction using NADPH – turns NADPH into NADP+
- Dehydration – loses H20
- Reduction using NADPH – turns NADPH into NADP+
each round of fatty acid synthesis adds how many carbons
2 carbons are added to the chain at a time
longest fatty acid synthase chain
16 carbon chains any longer requires special enzymes to add onto it
how many malonyl CoA are produced per acyl CoA
1 acyl CoA per 1 malonyl CoA
elongases
different enzymes that can add 2 carbon units to create chains longer than 16 carbons
desaturases
can introduce double bonds into fatty acids using
NAD(P)H and O2
mammals cannot introduce double bonds beyond carbon number 9
what cosubstrate that is not used the in overall reaction is require to make malonyl CoA
CO2
sources of amino acids
proteins from diet
degredation of defective or unneeded cellular proteins
What degrades proteins into individual amino acids
-availability of H2O and H+ helps denaturation of proteins through hydrolysis
proteases- variety of enzymes that break peptide bonds
Proteasomes- proteins tagged for destruction by peptide ubiquitin
how are proteins/amino acids stored
they are not stored, only utilized when needed and when availiable
amino acid utilizations
can be used as building blocks for new proteins
degraded - used for nitrogen
Amino acid degradation stpes
1) removal of nitrogen
2) Carbon skeletons
of 20 amino acids funneled
into 7 molecules
most all amino acids can be converted to what
alpha ketoglutarate which gets converteed to glutamate
can be interconverted and reversed as needed
deamination of glutamate
forms NH4 ammonia
regenerates alpha ketoglutarate
can be used to make amino acids to create urea (piss)
urea users
terrestrial vertebrates / sharks
uricotelic animals / uric acid users
birds / reptiles
Carbamoyl Phosphate Synthetase functions
creates carbanoyl phosphate which is used to create urea
uses 2 ATP
NH4 to NH3
carbon comes from HCO3 - hydrates CO2
where does the nitrogens from urea come from?
NH4 - ammonia
aspartate
urea cycle locations
mostly in cytosol
partly in mitochondrial matrix
Ketogenic Amino Acids
- can be degraded to acetyl CoA or
acetoacetyl CoA - can give rise to ketone
bodies or fatty acids, but
CANNOT be used to
synthesize glucose
Glucogenic Amino Acids
- can be degraded to pyruvate, ⍺-
ketoglutarate, succinyl CoA,
fumarate, oxaloacetate - these are later intermediates in the
TCA cycle
-can be converted into
phosphoenolpyruvate and
eventually glucose
phenylketonuria
-deficiency of phenylalanine hydroxylase
-leads to accumulation of phenylalanine because it cannot be converted to tyrosine
- therapy: low phenylalanine diet
ubiquitin
is a protein that signals for protein degradation by a proteosome
Aminotransferases contain which cofactor?
PLP
The nitrogens in urea generated from the
urea cycle come from
NH4+ and aspartate
A given amino acid is found to be metabolized to
yield acetoacetyl-CoA. What can be said about
this amino acid?
It is ketogenic
nitrogenase enzyme action and protein composition
-catalyzes the conversion of N2 to 2NH 3
-requires 16 ATP
-nitrogenase is a combination of the nitrogenase protein (MoFe protein) and reductase protein (Fe protein)
- the reductase oxidizes ATP to ADP for use in the nitrogenase
ways in which nitrogen is fixed
lightning
biochemically - nitrogenase
artifically - haber bosch
nitrogen assimlation
alpha ketoglutarate to glutamate which adds a nitrogen
glutamate to glutamine
glutamate to glutamine
adds side chain reaction
glutamine synthesis
after which nitrogen is then incorporated by aminotransferases
alpha ketoglutarate to glutamate
adds nitrogen
glutamate dehydrogenase
carbons are provided to amino acid synthesis how
provided by intermediates of glycolytic pathway TCA cycle and pentose phosphate pathway
amino acid synthesis in microbes vs humans
microbes - all 20 basic amino acids
humans - 9 amino acids can not be synthesized that are essential
tetrahydrofolate
carrier of activated one carbon units
essential for syntehesis of many amino acids and nucleotides
derived from vitamin B9
What does beta in beta oxidation mean
Beta refers to the 3rd carbon from the carbonyl group (which includes the carbon in the carbonyl group)
DNA characteristics
- semi conservative
- requires activated precursors
- initiation begins at origin of replication
- replication is bidirectional
- 5’ to 3’ direction
DNA polymerase
- requires a primer that has a free 3’-OH group
- needs activated nucleotides - dATP, dCTP, dGTP, dTTP
- creates phosphodiester linkages joining units to the DNA backbone
Meselson and Stahl experiement
found semi conservative replication
added radioactive nitrogen to both DNA strand
cut open new daughter cells
found it to be semi conservative
consensus sequence
order of repeated residues found in different positions