AP Biology - Unit 1

by: Gabe Parr

Cohesion

water is attracted and will bond with other water molecules(hydrogen bonds)

Polarity

property of water that is due to the unequal sharing of electrons between oxygen and hydrogen within a water molecule(gives hydrogen slightly positive charge and oxygen slightly negative charge)

7 Properties of Water

Polarity, Cohesion, Adhesion, Capillary Action, Temperature Control(High Specific Heat and High Heat of Vaporization), Density, Excellent Solvent

Basic Solutions

bitter taste, also referred to as alkaline, slippery/soapy feel

Acidic Solutions

sour taste, strong ones can dissolve metals and cause burns

Solution is Acidic if…

dissolving something in water causes it to have more H+ than OH-

Ionic Bonds

giving up or gaining of electrons to have a full valence(outer) shell *(weak)

Dissociation of Water

H2O —> H+(hydrogen ion) + OH-(hydroxide ion)

Solution

result of one substance dissolving into another substance

Isotopes

form of an element that has a different number of neutrons

Solvent

substance doing the dissolving in a solution

Polar Covalent Bonds

atoms share the electrons unequally (Ex: water)

Amino (Functional Group)

-NH2

Sulfhydryl (Functional Group)

-SH

Methyl (Functional Group)

-CH3

Characteristics of Hydrocarbons

nonpolar, not soluble in water, hydrophobic, stable

Isomers

molecules with same molecular formula, but different structure/chemical properties

Nonpolar Covalent Bonds

atoms share the electrons equally (balanced/stable)

Covalent Bonds

sharing of electrons to have a full valence (outer) shell *(strong)

Hydroxyl (Functional Group)

OH

4 Classes of Macromolecules

Carbohydrates, Proteins, Nucleic Acids, Lipids

Phosphate

PO4

Dehydration Synthesis/Condensation Reaction

process of joining monomers to a make a polymer by losing water

Hydrolysis

process of breaking a polymer into monomers by adding water (Ex: digestion)

Buffers

substance that when added to a solution enables the solution to resist changes in pH

6 Most Common Elements of Life

Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur

Hydrocarbons

simplest carbon molecules, combination of carbon and hydrogen

Macromolecules

large molecules formed by carbon

pH scale

acids 0-6 pH, bases 8-14 pH, neutral liquid = 7 pH, scale works by powers of 10

Carboxyl

-COOH

Solute

dissolved substance in solution

Carbonyl

C=O

Polymers

chain like macromolecules of similar or identical monomers that are covalently bonded together

Molecule

combination of two or more elements that are bonded together

Solution is Basic if…

dissolving something in water causes it to have more OH- than H+

Monomers

repeating units that make up polymers

Adhesion

water is attracted to other polar molecules and ionic substances(will form hydrogen bonds with them)

Capillary Action

the upward movement of water due to the forces of adhesion being greater than cohesion(surface tension also involved)

Temperature Control

High Specific Heat: water resists changes in temperature due to hydrogen bonds

High Heat of Vaporization: water requires a lot of energy to vaporize(transform liquid to gas) due to strong hydrogen bonds

Density

as water solidifies it expands and becomes less dense

Solvent (Property of Water)

water is an excellent solvent with other polar(hydrophilic) molecules and ionic substances(forms hydrogen bonds with them)

Living Systems need…

a constant input of energy in order to grow, reproduce, and maintain organization

All Organisms are built from the same 4 types of molecules. Which are…

Proteins, Carbohydrates, Lipids, and Nucleic Acids

Carbohydrates

Definition: main source of energy for living things

Polymers: sugars, starches, plant fiber(cellulose)

Monomers: monosaccharides(simple sugars)

composed of carbon,hydrogen,oxygen(1-2-1 ratio in monosaccharides)

Functions: energy, energy storage, raw and structural materials

General Carbohydrate Formula

(CH2O)x

Lipids

Definition: high energy, hydrophobic molecule

Polymers: fats, oils, waxes, cholesterol, steroid hormones

Important Building Block: fatty acids

composed of lots of carbon and hydrogen, little oxygen

Proteins

Definition: a polymer of amino acids, many diverse functions

Polymers: muscle tissue(meat), enzymes, antibodies

Monomers: amino acids

*most diverse macromolecules

*shape determines function

Monosaccharide

simple sugar (Ex: glucose)

Disaccharide

two monosaccharides joined together through a glycosidic linkage after dehydration synthesis (Ex: sucrose/table sugar)

Polysaccharide

multiple monosaccharides joined together through glycosidic linkages after dehydration synthesis that require little energy to build (Ex: starch)

Glycosidic linkage

type of covalent bond between sugars after dehydration synthesis

Glycogen

polysaccharide used for energy in animals

Diverse Groups of Lipids

fats, phospholipids, steroids

Structure of Fats

glycerol + fatty acids

Ester linkage

type of covalent bond that forms 3 times between a hydroxyl and carboxyl in a fat molecule

Saturated fats have…

no carbon double bonds

Unsaturated fats have…

carbon double bonds that will give a little bend in structure of fatty acid

Structure of Phospholipids

phosphate group + 2 fatty acids

Phospholipids Head vs Tails

Head = hydrophilic, Tails = hydrophobic

Structure of Steroids

4 fused carbon rings

Fats are…

non-polar(little amount of oxygen) and hydrophobic

Lipoproteins

combination of a lipid and protein, carries cholesterol around body

Low-density Lipoprotein (LDL)

carries cholesterol to body tissues, "bad" cholesterol

High-density Lipoprotein (HDL)

carries cholesterol away from body tissues, "good" cholesterol

Glucose and Fructose both act as energy sources and have…

the same chemical formula(C6H12O6), but different atom arrangements

Deoxyribose

5-carbon sugar that is found in DNA, storages genetic information

Ribose

5-carbon sugar that is found in RNA, takes genetic information from DNA in the nucleus to the ribosomes in the cytoplasm in order to make protein

Glyceraldehyde

3-carbon sugar that has a key role in both cellular respiration and photosynthesis

Fructose

6-carbon sugar found in fruit

Glucose

6-carbon sugar that is an important source of energy for living organisms

Chemical Formula of 2 Monosaccharides, both C6H12O6, combining through Dehydration Synthesis

C12H22O11

Purposes of Cholesterol

precursor of hormones, keeps cell membranes flexible

Functions of Proteins: C-MEATS

C: Contraction

M: Messenger

E: Enzymes

A: Antibodies

T: Transport/Storage

S: Structural

Structure of Amino Acids

Central carbon atom, left side: amino group, right side: carboxyl group, top: hydrogen atom, bottom: R-Group/Side Chain

R Groups of Amino Acids can be…

nonpolar(hydrophobic), polar(hydrophilic), charged/ionic

Peptide bond

type of covalent bond between amino acids after dehydration synthesis

Name of Ends of Polypeptide Chain

Starting End: N terminus (exposed amino functional group)

Ending End: C terminus (exposed carboxyl group)

Amino acid "residue"

what's left after an amino acid has been connected to a polypeptide chain after dehydration synthesis(whole amino acid without peptide bonds)

Polypeptide

multiple amino acids joined together by peptide bonds after dehydration synthesis

Primary Structure

"beads on a string", sequence of amino acids

*order of amino acids is determined by genes

*order determines the 3D shape of protein

Alpha Helix

secondary protein structure: corkscrew shape due to hydrogen bonding between the atoms of the amino acids of the polypeptide backbone

Beta Pleated Sheet

secondary protein structure: back-and-forth folded shape due to hydrogen bonding between the atoms of the amino acids of the polypeptide backbone

Tertiary Structure

3D folding due to interactions between R-Groups; mainly hydrophobic interactions but can also be hydrogen bonds, ionic bonds, and disulfide bridges

*3D folding establishes the protein's function

Quaternary Structure

2 or more polypeptides combined through weak bonds to make a more complex and stable protein structure (*found only in some proteins)

Why should the final shape of a protein be at a low energy state and not a high energy state?

Because at a high energy state, the protein will be unstable and easily break, while a protein that is at a low energy state will be stable.

Hydrophobic Side Chains in a Protein will…

bend and fold into the polypeptide backbone to shield themselves from the water

Acidic/Basic Side Chains in a Protein will…

come close together to neutralize each others charges

Cysteine Side Chains in a Protein will…

move closer together to form disulfide bridges

Hydrophilic Side Chains in a Protein will…

bend to the outside of the polypeptide backbone to be closer to the water

Electronegativity

atoms that are greedy for electrons (Ex: oxygen)

Hydration Shell

the sphere of water molecules around each dissolved ion

Molarity

common measure of solute concentration

Change in Amino Acid Subunits at the Primary Level of Structure will…

lead to changes in structure and function of the protein

Denaturation

protein loses its 3D shape due to changes in pH, increase in temperature, or salinity, causing it to unravel back to the primary structure

In the denaturing of a protein, the protein loses its original…

shape and function

Phospholipids are an important structural component of…

cell membranes

Cellulose

structural polysaccharide for plants

Chitin 

structural polysaccharide for fungus/arthropods 

Starch

polysaccharide used for energy in plants