Lec 4 Macromolecules (II) 1-6

Lec 4 Macromolecules (II) 1-6 - Biol 113 AU2011 A. Proteins...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Biol 113 AU2011 Lecture 4 Macromolecules (II) A. Proteins B. Nucleic acids A. Proteins Proteins account for more than 50% of the dry mass of most cells Protein functions include structural support, storage, transport, cellular communications, movement, and defense against foreign substances Figure 5.15-a Enzymatic proteins Defensive proteins Storage proteins Transport proteins Enzyme Virus Antibodies Bacterium Ovalbumin Amino acids for embryo Transport protein Cel membrane Function: Selective acceleration of chemical reactions Example: Digestive enzymes catalyze the hydrolysis of bonds in food molecules. Function: Protection against disease Example: Antibodies inactivate and help destroy viruses and bacteria. Function: Storage of amino acids Function: Transport of substances Examples: Casein, the protein of milk, is the major source of amino acids for baby mammals. Plants have storage proteins in their seeds. Ovalbumin is the protein of egg white, used as an amino acid source for the developing embryo. Examples: Hemoglobin, the iron-containing protein of vertebrate blood, transports oxygen from the lungs to other parts of the body. Other proteins transport molecules across cel membranes. Figure 5.15-b Hormonal proteins Function: Coordination of an organism’s activities Example: Insulin, a hormone secreted by the pancreas, causes other tissues to take up glucose, thus regulating blood sugar concentration High blood sugar Normal blood sugar Insulin secreted Signaling molecules Receptor protein Muscle tissue Actin Myosin 100 μ m 60 μ m Col agen Connective tissue Receptor proteins Function: Response of cel to chemical stimuli Example: Receptors built into the membrane of a nerve cel detect signaling molecules released by other nerve cel s. Contractile and motor proteins Function: Movement Examples: Motor proteins are responsible for the undulations of cilia and flagel a. Actin and myosin proteins are responsible for the contraction of muscles. Structural proteins Function: Support Examples: Keratin is the protein of hair, horns, feathers, and other skin appendages. Insects and spiders use silk fibers to make their cocoons and webs, respectively. Col agen and elastin proteins provide a fibrous framework in animal connective tissues.
Background image of page 1

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

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 01/05/2012 for the course BIO 113 taught by Professor Swenson during the Fall '08 term at Ohio State.

Page1 / 5

Lec 4 Macromolecules (II) 1-6 - Biol 113 AU2011 A. Proteins...

This preview shows document pages 1 - 2. Sign up to view the full document.

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