biochem pre lab quiz 4 and 3

What is Michaelis-Menten equation

Vo= Vmax[S]/km + [S]

What does km stand for

Substrate concentration when velocity is half Vmax

What does Vmax stand for?

Max velocity: rate of reaction when all active sites are filled by substrate.

What does Vo mean?

The speed of the enzyme reaction at the very beginning, before much substrate has been used up.

What’s the purpose of lab 3

To see how different amounts of Pyruvate affect the speed of the enzyme lactate dehydrogenase (LDH) and to determine it’d maximum reaction rate (Vmax) and km

What is the active unit for LDH

1 U= 1 mol of substrate converted per min

What reaction were we carrying out?

For lab 3

Carrying out the conversion of pyruvate to lactate replicating a step of anaerobic glycolysis using NADH as a cofactor and LDH as an enzyme

Why we studied this reaction and not the reverse for lab 3

This direction is spontaneous (negative delta G) under the lab conditions, making it easier to measure the reaction rate

What wavelength are we using and why for quiz 3

Using 340 nm because NADH absorbs light at this wavelength, but NAD+ doesn’t absorb much

Purpose of lab 4

To determine the degree of unsaturation in different oils and fats by calculating their iodine numbers using a titration

What is Wij’s equation and what is the first step

HC=CH + ICl —> CHI-CHCl

ICl reacts with C=C double bonds, converting them into single bonds by adding iodine (I) and chlorine (Cl)

Define Iodine number

The amount of iodine (in g) absorbed by 100g of fat or oil

Differences np between Cis and Trans in fatty acids

Cis unsaturated fats are generally healthier, while trans fats increase LDL (bad) cholesterol and the risk of heart disease

Where is fat stored in the body

Primarily stored as triglycerides in adipose tissue

How do Unsaturated and Saturated fats affect the membrane

Unsaturated makes “fluid-like” membranes

Saturated makes “gel-like” membranes

What is the cause of atherosclerosis

Caused by the bluidup of fatty plaques in artery walls

Leads to inflammation, narrowing of arteries and reduced blood flow

How can one be healthier in relation to polyunsaturates/saturates

By replacing some saturated fats with polyunsaturated fats is generally better for heart health

What lip is is most common in humans

Triglycerides