Lecture_4_proteins_4slides

Lecture_4_proteins_4slides - 1/26/11 READINGS : Systems...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
1/26/11 1 Systems Human Physiology Lecture 4: Protein interactions and enzymes 1 READINGS : TODAY: CHAPTER 3 Sections C-D Tuesday: CHAPTER 3 section E-F 2 Regulation of protein levels Protein interactions: Specificity Affinity Equilibrium Saturation Competition Enzymes Characteristics Regulation Today’s outline: 3 DNA RNA Protein transcription translation splicing/alternative splicing degradation RNA degradation Regulation of protein amount in a cell 4 There is also regulation at the level of protein activity - we will talk about that today
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
1/26/11 2 5 Protein Structures • Primary Protein Structure • Secondary Protein Structure • Tertiary Protein Structure • Quaternary Protein Structure 6 Conformation • Proteins do not appear in nature like a linear string of beads on a chain. • Interactions between side groups of each amino acid lead to bending, twisting, and folding of the chain into a more compact structure. • The Fnal shape of a protein is known as its conformation . Primary structure - amino acid sequence Secondary structure - local 3D structures Tertiary structure - complete 3D structure PROTEIN FOLDING α helix β sheet Quaternary structure - aggregation of several protein subunits 8 Primary Protein Structure Two variables determine the primary structure of a protein: (1) The number of amino acids in the chain (2) The specific type of amino acid at each position along the chain A polypeptide in the primary protein structure is analogous to a linear string of beads, each bead representing one amino acid.
Background image of page 2
1/26/11 3 9 Secondary Protein Structure The attractions between various regions along a polypeptide chain creates secondary structure in a protein. Because peptide bonds occur at regular intervals along a polypeptide chain, the hydrogen bonds between them tend to force the chain into a coiled conformation known as an alpha helix . Hydrogen bonds can also form between peptide bonds when extended regions of a polypeptide chain run approximately parallel to each other, forming a relatively straight, extended region known as a beta pleated sheet . 10
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/09/2011 for the course IB 132 taught by Professor Brooks during the Spring '08 term at University of California, Berkeley.

Page1 / 12

Lecture_4_proteins_4slides - 1/26/11 READINGS : Systems...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online