HI310 Lecture 2: Biology-Chapters-3-4-5-16-Study-Guide
24 Jan 2019
Department
Course
Professor
1
Biology Chapters 3, 4, 5, 16 Study Guide
Contents
Chapter 3 Notes .......................................................................................................................................... 2
‘Water’ ........................................................................................................................................................ 2
3.1 ........................................................................................................................................................... 2
3.2 ........................................................................................................................................................... 2
Chapter 4 Notes .......................................................................................................................................... 3
‘Carbon and the Molecular Diversity of Life’............................................................................................... 3
4.1 ........................................................................................................................................................... 3
4.2 ........................................................................................................................................................... 3
4.3 ........................................................................................................................................................... 4
Chapter 5 Notes .......................................................................................................................................... 4
‘The Structure & Function of Macromolecules’ .......................................................................................... 4
5.1 ........................................................................................................................................................... 4
5.2 ........................................................................................................................................................... 4
5.3 ........................................................................................................................................................... 5
5.4 ........................................................................................................................................................... 5
5.5 ........................................................................................................................................................... 5
Chapter 5 Review ........................................................................................................................................ 5
5.1 ........................................................................................................................................................... 5
5.2 ........................................................................................................................................................... 6
5.3 ........................................................................................................................................................... 6
5.4 ........................................................................................................................................................... 6
5.5 ........................................................................................................................................................... 7
Chapter 16 Notes ........................................................................................................................................ 7
16.1 ......................................................................................................................................................... 7
16.2 ......................................................................................................................................................... 8
Page 64-65 ................................................................................................................................................ 10
Hydroxyl: ............................................................................................................................................... 10
Carbonyl: ............................................................................................................................................... 10
Carboxyl: ............................................................................................................................................... 10
Amino: .................................................................................................................................................. 11
Phosphate: ............................................................................................................................................ 11
2
Chapter 3 Notes
‘Water’
3.1
Water is a polar molecule, meaning that opposite ends of the molecule have opposite charges.
The oxygen end has a partial negative charge, while the hydrogen ends have a partial positive
charge.
Since the slightly positive hydrogen is attracted to the slightly negative oxygen, the molecules
are held together by a hydrogen bond.
3.2
Water has four properties that contribute to the suitability of Earth as an environment for life,
these are:
1. Water’s cohesive behavior.
2. Its ability to moderate temperature.
3. Its expansion upon freezing.
4. Its versatility as a solvent.
Water bonds are bonded for only a trillionth of a second. However, they reform so quickly that
water is one of the strongest liquids around.
Collectively, the hydrogen bonds hold the substance together, a phenomenon called cohesion.
Cohesion, due to hydrogen bonding contributes to the transport of water and dissolved
nutrients against gravity in plants. Water from the roots reaches the leaves through a network
of water conducting cells. As water evaporates from a leaf, hydrogen bonds cause water
molecules leaving the veins to tug on molecules father down, and the upward pull is transmitted
through the water conducting cells all the way down to the roots.
Adhesion, the clinging of one substance to another also plays a role. Adhesion of the water to
the walls of cells helps counter the downward pull of gravity.
Surface tension also plays an important role, as water has a greater surface tension then most
other liquids.
Water moderates air temperature by absorbing heat from air that is warmer and releasing the
stored heat to air that is cooler. Water is effective as a heat bank because it can absorb or
release a relatively large amount of heat with only a slight change in its own temperature.
Anything that moves has kinetic energy.
Heat is the measure of the total amount of kinetic energy.
Temperature measures the intensity of that heat due to tea verge kinetic energy of the
molecules.
The ability of water to stabilize temperature stems from its relatively high specific heat.
Specific heat is defined as the amount of heat that must be absorbed or lost for 1 g of that
substance to change its temperature by 1°C.
Waters specific heat is 1 calorie per gram per degree Celsius. Abbreviated as 1cal/g/°C.
Due to the high specific temperature of water, relative to other materials, water will change its
temperature less when it absorbs o loses a given amount of heat.
3
Water resists changing its temperature; when it does change its temperature, it absorbs, or
loses a relatively large quantity of heat for each degree of change.
Water’s high specific heat can be traced back to its hydrogen molecules. Heat must be absorbed
in order to break hydrogen bonds and released in order to make the bonds.
When the temperature of water drops slightly, many additional hydrogen bonds form, releasing
a considerable amount of energy in the form of heat.
A large body of water can absorb and store a huge amount of heat from the sun in the daytime
and during the summer while warming up only a few degrees. And in the winter and at night,
gradually cooling the water can warm up the air.
Ice floats in water…this property of having a substance be less dense as a solid then a liquid is
very rare.
Water freezes when its hydrogen bonds are no longer able to move so vigorously so that they
can break their hydrogen bonds. The hydrogen bonds keep the molecules at ‘arms length’ just
enough so that it is less dense then its liquid form.
This ability of water is important because if ice sank on water then all the lakes and ponds would
freeze over. In the summer only the top few inches would thaw out while the rest of the ocean
below was solid ice.
Solution: A completely homogeneous mixture of two or more substances.
Solvent: The dissolving agent of a solution.
Solute: What the substance is dissolved into.
Aqueous Solution: One where water is the solvent.
Hydrophilic: Any substance that has an affinity, likes to be in, water.
Colloid: A stable suspension of fine particles in a liquid.
Hydrophobic: Non-polar substances that seem to repel water.
Molarity: The # of moles of solute per liter of solution.
Acid: A substance that increases the hydrogen ion concentration of a solution.
Base: A substance that reduces the hydrogen ion concentration.
Chapter 4 Notes
‘Carbon and the Molecular Diversity of Life’
4.1
Organic Chemistry: The branch of chemistry that deals with organic compounds. Organic
compounds are ones that contain carbon.
4.2
Carbon has 6 electrons, 2 in its first shell, and 4 in its valence shell. Since the second shell can
hold a total of 8 electrons, when binding with other atoms, Carbon will share 4 electrons.
Hydrocarbons: Molecules consisting of only Carbon and Hydrogen.
Isomers: Compounds that have the same number of atoms of the same elements but different
structures and hence different properties.
Structural Isomers: Differ in the covalent arrangements of their atoms. Structural isomers may
also differ in their location of double bonds.
