Exam 1 Study Guide

Exam 1 Study Guide - Thematic Questions How and why do...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Thematic Questions How and why do structures form? What is the relationship between structure and function? How do cells adapt to changes in the environment? How do physiological demands for energy alter metabolism? How and why are metabolic pathways integrated? You may use the outline which follows in different ways: • Answer the questions and add more detail as we cover each section. • Use it a skeleton outline initially then fill in the relevant sections as a pre-test (no notes), after you have done your studying for an exam. How much can you fill in without your notes? Learning Objective 1: By the end of Part 2 you should be able to address the following: How do molecules interact with one another? How does the cellular environment influence molecular interactions? Why do structures form? Discuss the relationship between structure and function of macromolecules. Provide examples to illustrate you understanding Part 1: A. Chemical interactions in biological systems Covalent vs. noncovalent interactions Types of bonds a) covalent bonds i. stable ii. typical energy released: 50-200 kcal/mol iii. shared arrangement of electrons o equal sharing, uniform charge distribution: molecule is nonpolar o unequal sharing, asymmetrical distribution: molecule is polar because the bond involves an electronegative atom: O>N>S>C>P>H b) ionic bonds i. electrons are not shared but rather transferred from one atom to another ii. atoms are bound together by the attraction between oppositely charged ions c) noncovalent interactions i. types o hydrogen bonds o electrostatic, ionic interactions o Van der Waal forces o hydrophobic interactions ii. why are they important? o weak and transient--gives macromolecules flexibility o provide stability to macromolecular structures--large number are present in a molecule; unlikely that all will be broken at the same time. o essential to specificity and catalytic efficiency of enzymes(biological catalysts) Electronegativity a) tendency of an atom or functional group to attract electrons Polarity a) leads to noncovalent interactions b) explains why molecules are hydrophilic or hydrophobic
Background image of page 1

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

View Full DocumentRight Arrow Icon
Hydrophobic effect a) entropy driven association b) hydrophobic interactions form spontaneously c) cell membranes form because of the hydrophobic effect d) cannot form H bonds with water; avoids water e) attraction between nonpolar molecules f) rather than dissolve in water(which decreases the entropy of water), nonpolar substances are excluded from water; that is their assembly is stabilized by hydrophobic interactions Van der Waals forces a) charge fluctuations (+) or (-) poles even in nonpolar molecule b) present with "snug fit" between atoms c) weakest of noncovalent interactions (0.1-1 kcal/mol) Electrostatic, ionic interaxctions a) attraction/repulsion of charges b) occur between atoms with a complete (-) charge and a complete (+) charge c) strength of interaction determined by distance and solvent
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/19/2012 for the course BIO 2000 taught by Professor Ewr during the Spring '12 term at Alabama.

Page1 / 7

Exam 1 Study Guide - Thematic Questions How and why do...

This preview shows document pages 1 - 3. Sign up to view the full document.

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