Enzyme - biology question?

Question

Ok i'm not sure about the wording of this question, what am i suppose to say?

An enzyme, such as amylase, has a specific 3d shape. Explain how DNA structure determines the specific shape of enzymes.

Thanks,
Jo

Answer 1

I am not sure myself whether your question is worded correctly - do you mean DNA structure or protein structure?

Technically speaking DNA structure has absolutely no effect on the shape of the protein - what's important is the sequence of the DNA as that will determine the sequence of the mRNA, which thus determines the sequence of the amino acids of the protein itself.

The protein structure is basically determined by its sequence of amino acids. Amino acids are basic, acidic, nonpolar, or polar - they all have different attributes but the key here is that each behaves differently. When they are being tacked onto a developing/elongating protein, they automatically fold into a shape so as to obtain the lowest state of free energy (remember than free energy determines nearly all chemical reactions). Polar amino acid residues then to stick out into the solvent as loop structures while nonpolar amino acids tend to group/huddle together and avoid any contact with the environmental solution. Amino acids such as proline actually causes a big 'kink' or bend in the protein chain simply because that amino acid makes a covalent bond back onto the main protein chain itself.

-Kevin

Answer 2

It doesn't, DNA codes the sequence of amino acids which is called primary structure. After being synthesized, the "pre-protein" either assumes it's shape spontaneously due to natural bonding or has another enzyme help it out. For large proteins the assembly is done outside the cell since the only way they can get out is to thread their way through channels in the cell membrane.

Answer 3

DNA is a template for mRNA (Transcription)
mRNA is used to synthesize a protein (Translation)
Amino acid sequence (through primary, secondary, tertiary structure) determines the 3D protein configuration