Can you help me explain that enzymes are globular proteins which act as catalyst? ?

Question

What exactly is a globular protein, would be a good place to start? thanks.

Answer 1

Peter S has a good explanation of the structure of globular proteins  and the relationships of primary , secondary amd tertiary structures. If you are implying that all enzymes are globular...that is NOT true. As an example, pyruvate dehydrogenase is a membrane bound high molecular weight ( > 5  X 10^6 Daltons ) enzyme complex that cannot be solubilized in aqueous phases..yet has a large turnover number and is a very tightly regulated enzyme

Answer 2

Yeah, take all the above comments. they're all correct. but i'll try to explain in laymen's terms.

enzymes are proteins (duh). Proteins can be divided into 2: globular or fibrous. Being globular, the enzymes are soluble in water, has spherical shape and vulnerable to denaturation by extreme heat or pH. Fibrous proteins will have different properties.

Catalyst is a chemical substance that speeds up a chemical reaction/metabolic processess without itself being used up. When we chew bread, it can take FOREVER for it to be broken down chemically from starch to glucose. However, the salivary amylase is the enzyme that speeds up the chemical digestion so that it proceeds in shorter time. Most of the metabolic processes in our body require enzyme. without them, they'll proceed very very slowly to maintain life.

Answer 3

There are four types of protein structure:

Primary: sequence of amino acids in the chain

Secondary: the shape of the protein molecule caused by hydrogen-bonding between -C=O and -N-H groups within the chain

Tertiary: the interaction between R-groups that causes folding and bending

Quarternary: interactions between protein subunits that result in the protein being classified as fibrous, globular or conjugated.

Globular proteins exhibit the above levels of folding and as a result have a precise 3-D shape - round and globular and soluble. Because of their folding they have a specifically shaped region in their structure where the substrate binds  = the active site.

Answer 4

Globular proteins are soluble in aqueous solution. Enzymes are globular proteins means that they are soluble in aqueous solution. And as catalyst they speed-up the metabolic or catabolic reactions which would otherwise take long time to get completed...