BIO EXAM 1

Intro to Bio, Chem., Water properties, Carbon, Macromolecules

Define 5 properties of life

• Order

• Evolutionary adaptation

• Regulation

• Energy

• Growth, development, & reproduction

Define Levels of life

1. Biosphere

2. Ecosystem

3. Communities

4. Populations

5. Organisms

6. Organs, Organ systems

7. Tissues

8. Cells

9. Organelles

10. Molecule

11. Atoms

Define Taxonomy

Naming & grouping of living things

Darwin’s book

“On the origin of species by means of natural selection” 1859

Darwinist principles

1. “Descent with modification”

2. Natural selection causes descent with modification

   Themes of unity and diversity

Identify the 2 types of sciences

1. Experimental Science: Hypothesis and answers

2. Discovery science: Describes natural structures and processes. 2 traits:

   1. Qualitative) Descriptions over metrics

   2. Quantitative) Metrics over descriptions

What is a element

Raw substance of nature, the building blocks

What is a compound

2/+ elements in a fixed ratio

Anatomy of an atom

1. Protons determine the element and periodic order

2. Neutrons determine the isotope and atomic mass

3. Electrons determine the chemical behavior

Atomic #

# of protons in nucleus

Atomic mass

• Protons + Neutrons of the elements most common isotope

  • Ex. Carbon 12 12.011 g (6 protons, 6 neutrons)

Mass #

• Total element mass of particular isotope

  • Carbon-14 (6 protons, 8 neutrons)

Identify electron properties

• Valence electrons determine chemical behavior

• Elements want to be inert/full (octet rule)

Covalent bonds

1. Covalent

   1. Sharing of valence electrons between atoms

Define Ionic bonds, and examples

1. Ionic

   1. Bond between Cation and anion ions

   2. Ions are charged atoms/molecules

   3. Salts are Ionic compounds with ionic bonds

Define Hydrogen bond

1. Hydrogen bonded to one atom is attracted to another atom

   1. Ex. Hydrogen peroxide with H2O cuz O-H bond

   2. Polarity relationship with Hydrogen bonds

Define electronegativity

Atom’s attraction for electrons in a covalent bond

Define polar/non-polar covalent bonds

1. Non-polar

   1. Atoms share electrons equally

2. Polar

   1. 1 atom is more electronegative

   2. Atoms aren’t shared equally

   3. The unequal sharing causes a partial ±charge for each atom/molecule

Cohesion

Bonded h20 molecules held by hydrogen bonds

Adhesion

Attraction by different substances

High specific heat

• Hydrogen bonds absorb heat when they break and releases heat when formed

  • Unit: calorie/gram / Celsius

Heat of vaporization (optional)

Hydrogen bonds break for evaporation of water

Solubility

Attraction to ionic and polar compounds; Dissolution in such substances

The density of Ice

Hydrogen bonds account for the spacious gap between h20 molecules in ice

Define evaporative cooling

• The process of a Liquid to Gaseous state; Helps stabilize temperature in organisms and environment

• “As a liquid evaps., it loses energy, thus becoming cool in the process.”

Water as a solvent/ soln.

1. Solns: Homogeneous mixture of substances

2. Solvent: Dissolving agent; does the dissolving

3. Solute: Reactive agent; Is dissolved

4. Aqueous solns are where water is the solvent

Hydrophilic/ Hydrophobic

1. Hydrophilic) Likes water

2. Hydrophobic) Hates water

Acid/Bases

• Determined by presence of H+ / OH- ions

• Acids) More H+ ions, pH 1-6, reduced OH- ions

• Bases) More OH- ions, pH 8-14, reduced H+ ions

Define buffers

• Minimizes changes in concentrations of H+/OH- ions

• Most buffers consist of an acid-base pair that reversibly combines with H+ ion

Define carbon skeleton

AKA carbon chain; Vary in length and shape w/ diff. functions

Define hydrocarbons

• Organic molecules of only carbon and H+ ions

  • Ex. Fats

  • Can undergo processes to release a lot of energy

Isomers vs Entantiomers

1. Compounds w/ same formula but diff. structure

   1. Structural isomers) L-shape carbon chain vs I-shaped

   2. Geometric isomers) Same arrangements, but position of elements vary

   3. Enantiomers) Mirrors images of each other

Define functional groups

• Components of organic molecules that are most commonly involved in chemical rxns

• Func. groups give molecules distinct properties

ATP

Adenosine triphosphate; “Energy shuttle of our cells”

Define the 4 macromolecules

• Macromolecules are large molecules of thousands of covalently bonded atoms

  1. Carbs) Serves as fuel, building material

  2. Lipids) Biological molecules which don’t form polymers; Commonly hydrophobic

  3. Proteins) Accounts for more than 50% of dry mass of most cells

     1. Support, storage, movement, etc.

     2. Consists of 1/+ polypeptides

  4. Nucleic acids) DNA & RNA

Define polypeptide & bond

Polymers built from the 20 different amino acids linked by peptide bonds

• Peptide bond) chemical bond joined by a carboxyl group to another amino group

• Short chains of amino acid

What is a polymer/ monomer?

1. Polymer includes Carbs, Proteins, Nucleic acids

   1. Large molecules made of large repeating subunits called Monomers

2. Monomers are bonded via a condensation/ dehydration rxn; Water is lost

Simple carb vs Complex

1. Simple carbs) Monosaccharides, single sugars; Multiples of CH2O

2. Complex carbs) Polysaccharides, complex sugars

What is a dissaccharide

Formed when a dehydration rxn joins 2 monosaccharides; When h2O is a product in the rxn and not the reactant (hydrated rxn)

What is a enzyme

• Proteins that catalyze chemical rxns

• Functions endlessly “Workhorse”

• Doesn’t change the net yield of a chemical rxn

Define hydrolysis

Reverse dehydration rxn; water as a reactant and not a product; h2O input

What are the 4 polysacharrides?

1. Starch) Storage polysaccharide for plants, polymer of glucose

2. Cellulose) Structural polysaccharide, insoluble, polymer of glucose

3. Chitin) found in exoskeleton of arthropods, structural support for fungi cell wall, also a structural polysaccharide

4. Glycogen) Animal counterpart to starch, stored in liver and muscle cells

What is a fat

1. Made up of 2 molecules

   • Glycerol) 3-carbon alcohol w/ hydroxyl group attached to each carbon

   • Fatty Acids) Carboxyl group attached to a long carbon skeleton

     • Varies in length, #, and location of double bonds

Define saturation/ Triglycerides

1. Saturated) no double bonds, maximum # of hydrogen atoms possible

2. Unsaturated) At least 1 double bond, lesser hydrogen atoms

Define phospholipids

• 2 fatty acids and a phosphate group attached to a glycerol

  • Fatty acid tails are hydrophobic whereas the phosphate group and attachments are hydrophilic

  • Can form membranes

Define steroid

• AKA Alcohols

• Lipids w/ a carbon skeleton of 4 rings

Define cholesterol

Present in animal cell membranes, maintains correct cell membrane fluidity

Define amino acids

Differ in properties due to different side chains “R groups”

• Central skeleton consists of Carboxyl group and a amino group and a carbon atom

Identify protein structure

• Smallest to biggest

1. Primary structure

2. Secondary structure

3. Tertiary structure

4. Quaternary structure

• Amino acids from polypeptides which then build up proteins

Denaturation

Unraveling of a protein or loss of a protein’s native structure due to environmental factors such as salt concentrations or temp.

DNA/RNA

1. DNA) Provides its own directions for self-replication

   1. Also directs synthesis of messenger RNA, which controls protein synthesis

Nucleotides

• Nucleic acids(DNA) are a polymer of nucleotides, consists of:

  • Nitrogenous base

  • Pentose sugar (5-carbon)

  • Phosphate group

Nitrogenous bases

1. Pyrimidines

   1. Cytosine C

   2. Thymine T

   3. Uracil U

2. Purines

   1. Adenine A

   2. Guanine G

DNA double helix

Molecule which is 2 polynucleotides spiraling around an imaginary axis

• Antiparallel) arrangement of 2 backbones running in opposite directions

• A-T, G-C nitrogenous base pairs

T/F DNA are nucleic acids, Nucleic acids are not DNA

True

T/F Protein encodes genetic info.

False

Define a polar molecule

When both ends have opposite charges ±

Trace elements

Elements required by organisms in small amounts

• Ca, P, S, K

Science vs Tech.

• Science) Discovery

• Technology) Invention