Biochemistry OA review
Types of enzyme regulation
Phosphorylation
Dephosphyorylation
Feedback inhibition
Competitive inhibitor
Non competitive
... [Show More] inhibitor
Chaperones
protein helpers that help folding of complicated protein structure they bind to newly made polypeptides and enable proper folding
Protein structures are stablized by:
the hydrophobic effect with van der waals interactions
Disulfide bonds can be found in:
proteins secreted from a cell: insulin
structural purpose proteins: keratin skin hair nails
Denaturation
the los of secondary, teritary, and quatirary structure-primary structure remains intact.
They do lose their ability to fx properly though
Why does denaturation happen?
Heat exposes hydrophobic bonds to water outside of a protein cauisng the amino acid to clump together and aggregate
Hydrogen and Ionic bonds can be broken how?
by changes in salt and PH concentration
-protein doesn't aggregate but it does cause protein to not be fxn.
How can disulfide bonds be broken?
by reducing agents (i.e.chemicals)
Heat breaks which bonds?
Hydrophobic interactions (effect)
Changes in PH changes which bonds?
Ionic and hydrogen bonds
High concentrations of NA+ affects which bonds?
Ionic and H+ bonds
Primary structure is held together by which bonds?
peptide bonds
Secondary structure is held together by which bonds?
Hydrogen bonds
Teritary structure is held together by which interactions?
R-side chain interactions
What enviornmental factors affect enzyme activity?
Temp
PH
substrate concentrations
Coenzymes
competitive inhibition
a molecule that resembles the normal substrate and competes for active sight of the enzymes
non-competitive inhibitor
Does not interact w/substrate nor active sight of the enzyme
-Attaches to different area of the enzyme and changes the shape of the enzyme.
Induced fit
enzymes adjusting their active site conformation slightly as the substrate bind to improve the fit-it adjusts to form itself around the substrate more tightly
What affects how active an enzyme is?
the closer an environment is to the optimal environment for an enzyme, the more active it is
Cofactor/Co-enzyme
an additional binder that helps an enzyme function before it can operate4 on the substrate
Kinases do what to phosophate?
it adds a phosphate group
-turns enzyme on
What do phosphatases do?
They remove phosphates
turn off enzymes
Myoglobin
contains a heme group with an iron atom and bind to one molecule of O2
and contains a porphyrin (carbon and nitrogen ring system) every one of the C bonds is double bonded
What causes myoglobin to absorb light well?
O2 is bound to it with carbon nitro. ring system
Non-oxygenated blood color?
purple color
Oxygenated blood color
scarlet color
Oxidized blood color
brown
Fxn of myoglobin
Where is it stored
How does it bind to o2
Oxygen storage
stores in the muscle cell
binds to o2@ low o2 levels tightly (its reaches saturation quickly)
Hemoglobin fxn
oxygen transport
How much subunits to o2 molecules for hemoglobin?
4 subunits =4 o2 molecules
What two states does hemoglobin exist in and why?
1.R-state (relaxed) oxygen in bound to it- it attaches to the heme complex and causes it be planar
2. T-state (stressed state) oxygen is not bound to it; the FE atom pulls on it and causes it to slightly bend altering the light absorption of the porphyrion ring giving venous blood a deep purple color
How does hemoglobin differ from myoglobin in concentration?
Require a much higher o2 concentration to bind
binds tightly to o2 in the lungs
What molecules influence the affinity of hemoglobin for o2? What state does it cause it to be in (T or R)? which way would it cause the curve to shift?
CO-stablizes the "R" state-shifts left
2-3 BPG stabllizes the "T" state-shifts right
H+stables the "T" state-shifts right
------These contribute to the Bohr effect and the impact Ph has on O2 binding
Myoglobin graph is
hyperbolic shape
---it increase rapidly
--direct relationship with Po2- and the Po2 increases the binding of o2 to myoglobin increases to (90% saturated at 20 torr.)
How would the o2 carrying capacity be meausred?
Hemotocrit and % blood volume
Normal ranges: 40% women, 45% men
Graph of hemoglobin
Sigmodial shape
Why does hemoglobin has a low o2 affinity
because of it quaternary structure
T state favor which environment and what is the effects
Favors low PH (highly acidic environment; H+ concentrations)
-Low affinity for o2 in this state
-induces o2 release
-this o2 is picked up by cells in need of o2
-Hb releases 10% more o2 at Ph of 7.2 compared to 7.4
--MORE CO2 means MORE acidic
R state favors which environment and what is the effects
Favors high Ph (More basic; less H+ concentrations)
-High affinity for o2 in this state
-stimulates the binding of o2; o2 binds more tightly as PH increases
---As acidiosis occurs less o2 is being circulated, this causes the o2 on Hb to remain bound (it wont release) This decreases o2 affinity for o2-thus CO increases
Myoglobin has which helices?
Alpha helices
Hemoglobin has which helices?
Alpha and beta helices
What makes fetal Hb different?
It doesn't bind to 2,3BPG. B/c of this the fetal Hb has a higher affinity for o2.
It binds tighter to o2 than the mother
What role does 2,3 BPG has on o2?
It stimulates o2 release in the tissues
--it binds to the deoxy. form of Hb and stablizes the T state-->this causes a decrease in the Hb affinity for o2 which allows more o2 in the tissues
---decrease o2 affinity
---allows o2 to be released.
Sickle cell is mutation of which subunit for which protein?
Beta subunit of Hb
Metabolic pathway
series of biochemical rxn needed to go from raw material to final product
catabolic pathway
break large molecules down
include "lytic"
releases energy trapped in chemical bonds
Which bonds contain the highest amt of energy in the form of ATP?
bonds between phosphates
Anabolic Pathway
Pathways THAT USE energy from ATP to build compounds
-include the "genesis"
When o2 is available which can be broken down to yield a two-carbon unit that form a molecule of Acetyl-CoA
Glucose, Fatty acids, and Amino acids
When o2 is not present which can can be broken down to produce ATP and Acetyl-CoA? What is that called?
Glucose
Glyoclysis
Where is Acetly-CoA brokendown? What is the process called?
In the mitchondria
-Citric acid cycle or Krebs cycle
example of monosaccharide
glucose, fructose, galactose
example of disaccharide
sucrose, lactose, maltose
Example of polysaccharide
starch, glycogen, cellulose
How many carbons does a monosaccarhide have?
3-6
poly saccharides w/alpha links:
amylose (starch) [Show Less]