Bio240%20January17

Bio240%20January17 - Two slow-moving predators that use...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Two slow-moving predators that use molecular weapons to capture fast-moving prey How do slow moving puff adders catch their prey? Injected toxin components attack cells in the victims body But what do these toxins target? Figure 2.1 The structure of a cell membrane Plasma membranes -separate the cell cytoplasm from the extracellular fluid , intracellular membranes separate compartments within a cell ( organelles )
Background image of page 1

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

View Full DocumentRight Arrow Icon
2 Figure 2.2 The structure of membrane phospholipid molecules (Part 2) Phospholipids have hydrophilic (water loving) polar heads and hydrophobic (water hating) nonpolar tails Figure 2.2 The structure of membrane phospholipid molecules (Part 1) The phospholipid heads are hydrophilic due to phosphate groups that make the electron distibution of the head uneven (polar), whereas the tails are non-polar and thus hydrophobic -ve +ve Unsaturated hydrocarbons (double bonds) produce bends that add to membrane fluidity The phospholipid composition of membranes is diverse and phospholipids freely diffuse within membrane leaflets. The degree of fluidity is a function of phospholipid composition and temperature.
Background image of page 2
3 Figure 2.3 Degree of unsaturation of brain phospholipids in fish varies with habitat temperature Increasing the levels of unsaturated hydrocarbon tails in brain cell membranes allows membranes to be flexible at cold temperartures Figure 2.1 The structure of a cell membrane Puffer adder venom contains a phospholipase enzyme that breaks down skeletal muscle membranes Membrane proteins (integral and peripheral) endow membranes with many functional capacities
Background image of page 3

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

View Full DocumentRight Arrow Icon
4 1. Channels and 2. Carriers Five functional types of membrane protiens 3. Structural proteins 4. Receptors 5. Enzymes Channels permit diffusion of solutes/water across membranes Transporters alllow covalently bound ions/moleclues across the membrane via active transport (requires energy) Anchors bind other proteins to hold them at functionally important sites (eg synapses, cell junctions) Receptors bind signalling molecules non-covalently intitiating changes leading to signal transduction (eg ion permeability, metabolic events) Enzymes catalyze chemical reactions in which covalent bonds are made/broken Box 2.1, Figure A The structural hierarchy of proteins (Part 1) The primary structure of proteins are made up of amino acids linked by strong covalent bonds (amino acids share electrons) Secondary and tertiary structure generally rely on weaker noncovalent bonds and are therefore somewhat flexible Some proteins act as subunits, binding other subunits to provide quaternary structures
Background image of page 4
5 Figure 2.4 Structure of a transmembrane protein illustrating several modes of presentation (Part 1) Membrane proteins often have repeated structural domains Figure 2.4 Structure of a transmembrane protein illustrating several modes of presentation (Part 2) Membrane proteins often associate with other integral and peripheral proteins
Background image of page 5

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

View Full DocumentRight Arrow Icon
6 Figure 2.5 Simple epithelia (Part 1) Body organs and tissues are bound or separated by sheets of epithelial cells
Background image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/29/2008 for the course BIOS 240 taught by Professor Richmond&warphea during the Spring '08 term at Ill. Chicago.

Page1 / 23

Bio240%20January17 - Two slow-moving predators that use...

This preview shows document pages 1 - 7. Sign up to view the full document.

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