Biochem Flashcards
What is the induced fit model
model that assumes that enzymes have a flexible conformation.
What is a haloenzyme
a protein that requires a nonprotein cofactor to work.
Haloenzyme= apoenzyme + cofactor.
Enzymes that catalyze a redox reaction are called
Oxidoreductases
Enzymes that transfer a functional group are called
Transferases
Enzymes that cause hydrolisis reactions are called
Hydrolases
Enzymes that break C-O, C-C or C-N bonds
Lyases
enzymes that transfer high energy phosphates
Kinases
Enzymes that rearrange functional groups
Isomerases
Enzymes that join two molecules
Ligases
What is Km
The Michaelis constant.
numerically equal to the substrate concentration that gives half maximal velocity.
For most enzymatic reaction what is the value of Km
Bn 10^-1 and 10^-6 M.
What is the name of the Michaelis-Menten eq written as an equation of a line.
Lineweaver-Burk equation.
How are Vmax and Km affected by a competitive inhibitor
Vmax; remains the same
Km; increases, because of needed increase in [S]
How are Vmax and Km affected by a non-competitive inhibitor and an irreversible inhibitor
Vmax; decreases
Km is unchanged
For an irreversible inhibitor the changes are permanent.
What is the name of enzymatically inactive precursors of proteolytic enzymes
Zymogens
What are the three subunits of a G-protein
Alpha
Beta
Gamma
What are four fat soluble vitamins
A
D
E
K
What disease can cause Vit D excess
Sarcoidosis
What is the most toxic vitamin
Vitamin D
“D for danger”
What is the active form of vitamin D
1,25-dihydroxycholecalciferon
Deficiencies in vit B can cause
Dermatitis
Glossitis
Diarrhea
What is wet beri-beri
high output cardiac failure; leads to edema
What is dry beri-beri
Problems in the PNS, leading to progressive paralysis and muscle waisting.
Presents as polyneuritis.
What is Wernicke-Korsakoff syndrome
problems in CNS leading to ataxia, memory loss and confusion.
Vit BI deficiency can lead to
Wet or dry beri-beri
Wernicke-Korsakoff
α amylase converts
starch to oligosaccharides
What converts maltose to dextrins
ß amylase
what converts starch to glucose
glucamylase
what is another name for salivary amylase
ptyalin.
secreted by Parotid gland (PTyalin= ParoTid)
What are two α amylase examples
salivary amylase
Pancreatic amylase
-they only break starches into smaller components (oligosaccharides) but not individual sugars.
Glut-1
Present in most cells.
Glucose transport into RBCs and through BBB
Glut-2
Liver and pancreatic cells
Glut-3
Main transporter in neurons
Glut-4
Muscle and adipose tissue.
-regulated by insulin
Glut-5
Transports fructose into testis and intestines
What are three ways to make ATP
Substrate level Phosphorylation.
Oxidative phosphorylation
Photophosphorylation
What are the three irreversible enzymes in glycolysis
Hexokinase
PFK-1; Phosphofructokinase-1
Pyruvate Kinase
