Honors Biology Unit 1: Biochemistry

• The basic unit of life is the cell, which is composed of various biomolecules including carbohydrates, proteins, lipids, and nucleic acids that perform essential functions.

Bonding:

Matter- Anything with mass and takes up space.

                        -Atoms: Smallest unit of matter.

                        → Protons- Positive (Nucleus)

                        → Neutrons- Neutral (Nucleus)

                        → Electrons- Negative (Electron shell)

-Atoms are electrically neutral, meaning they have the same number of protons and electrons.

Elements: Made up of one type of atom

-Carbon            -Phosphorous

-Oxygen           -Nitrogen

-Hydrogen        -Calcium

Atomic Interaction:

-Done by valence electrons (Outermost electrons)

        →Shared electrons-Covalent Bond

        →Donated/Received electrons-Ionic Bond

-Isotope: Atoms with the same number of protons, but different number of neutrons

               -Carbon 12- 6p 6n 6e

               -Carbon 13-6p 7n 6e

               -Carbon 14-6p 8n 6e

-Carbon dating: Determines the age of fossils

→H2O

    →Octet rule: Atoms want 8 valence electrons

Ionic Bonds: (Metals and Non-metals)

-Transferring electrons

-Ions are atoms with charges→ Two types

        →Cation(+)

        →Anion(-)

       Covalent Bond: (2 Non-metals)→Sharing electrons

        →Polar: Unequal sharing

        →Non-polar: Equal sharing (That’s why oil and water don’t mix, because oil is non-polar while water is polar)

Water and its solutions:

Water:

-Forms hydrogen bonds

-Polar

-Solid form is less dense than the liquid form

Water molecule:

-Polar molecule

            →Polar covalent bond- Electrons are unequally shared between atoms

                          -Oxygen pulls the electrons closer to it as opposed to hydrogen

                                          →O=Partial - H=Partial +

-Hydrogen bond: Attraction of a slightly positive hydrogen atom to a slightly negative atom (Oxygen, Nitrogen, or Fluorine)

Cohesion and adhesion:

-Cohesion: Attraction of water molecules to one another

-Adhesion: Attraction of water molecules to the sides of the container.

                →Together, they cause surface tension (Liquid surfaces minimizing their surface                     area).   

Capillary action:

-Cohesion and adhesion acting together to allow water to move against the force of gravity.

Heat capacity and living things:

-Water has a high heat capacity

•     Takes more energy to cause it to boil due to the hydrogen bonds

• Living things are 60-70% water

• Nearly every chemical reaction in living things takes place in water

Solutions:

-Mixture: Two or more elements that are not chemically combined and not in a specific ratio.

-Solution: Mixture in which all components are evenly distributed.

                →Solute: Dissolved

                →Solvent: What is doing the dissolving

Suspensions:

-Mixture in which molecules don’t dissolve; able to settle out of the mixture

Ex. Blood and muddy water

pH scale:

-Used to determine the concentration of H+ ions in a solution

-Low= more acidic High=less acidic

Acids and Bases:

-Acids are a compound that releases H+ ions in a solution

→pH below 7 Ex. Lemon juice and vinegar

-Bases are compounds that release OH- ions in a solution

→pH above 7 Ex. Bleach and soap

Buffers:

-Weak acids and bases that resist changes in pH

        -The body is filled with them

                            →Keeps sharp changes from happening

                                            -Bicarbonate buffer

                                            -Phosphate buffer

Macromolecules:

Carbon:

-Essential to life

-All organic compounds contain carbon

Characteristics of carbon:

4 valence electrons

-Can form bonds with 4 atoms at once

-Variety of bonds with a variety of elements

Carbon forms a variety of molecules:

-Chains

-Rings

-single, double, triple bonds

    →Forms bonds with: Hydrogen, Oxygen, Nitrogen, and Phosphorous

Macromolecules:

-Big organic molecules in living things

→ most are formed by polymerization (Converting monomers to polymers)

-Monomer: small units that join together to form polymers

-Dehydration synthesis: Taking out water in order to build a covalent bond

-Hydrolosis: Using water to destroy a covalent bond

Types of macromolecules:

-Carbohydrates-Quick energy

-Lipids-Energy storage

-Proteins-Build and maintain muscle tissue

-Nucleic acid-Storing genetic material

Carbohydrates:

-Sugar

-Starch

-Cellulose

→ Hydrogen, Oxygen, Carbon.

-In a 1:2:1 ratio

3 types:

-Monosaccharide: Glucose, Fructose, Galactose

-Disaccharide: Lactose, Maltose, Sucrose

-Polysaccharide: Starch, Glycogen, Cellulose

                → Starch and cellulose reside in plants, while glycogen is excess sugar in animals

Glycosidic bond: Bond between 2 sugars

-Simple carb test: Benedict’s

-Complex carb test: Iodine

Lipids: Fats

-Organic

-Non-polar

-Not water soluble

Elements:

-Carbon

-Oxygen

-Hydrogen

-Not in a 1:2:1 ratio

Monomers: Polymer→Triglyceride: 1 glycerol + 3 fatty acid chains

-Glycerol

-Fatty acid

Energy: Carbs and lipids are the biggest energy molecules

-Carbs: 4kcal/molecule

-Lipids: 9kcal/molecule

-Ester bond: Bond formed between glycerol and fatty acids

Functions:

-Energy storage

-Insulation

-Waterproofing

-Cell membrane

-Chemical messengers

Saturated fats:

-Single bonds in the fatty acid chain

-Solid at room temperature

-Animal fats

Unsaturated fats:

-One or more double bonds

-Liquid at room temperature

-Plant-based fats

Steroid hormones:

-Estrogen

-Testosterone

Cell membrane:

2 ways:

-Cholesterol: Gives structure

-Phospholipid: Makes up the majority of the cell membrane

  -Brown paper bag test: If translucent when held up to a light, lipids are present

Proteins:

-One of the largest most diverse macromolecules

Elements:

-Carbon

-Hydrogen

-Oxygen

-Nitrogen

Monomer: Amino acids (there’s 20 different types)

R-group-Caries with each amino acid. It’s what changes when the amino acid changes

Peptide bond: Carbon + Nitrogen covalent bond

Levels of organization:

-Primary structure: Linked amino acids

-Secondary structure: Alpha helix or Beta sheet

-Tertiary structure: 3-D structure (protein becomes functional)

-Quaternary structure- 2 or more tertiary proteins put together

Nucleic Acid: DNA and RNA

-Stores genetic info.

Monomer: Nucleotide

Elements:

-Carbon

-Hydrogen

-Oxygen

-Nitrogen

-Phosphorous

DNA: Adenine, Thymine, Cytosine, Guanine

RNA: Adenine, Uracil, Cytosine, Guanine

Enzymes:

Chemical reactions- Using one set of compounds to create a new substance

-Rearranging what atoms are connected to

-Reactants: What you start with

-Products: What you end up with

Energy:

-Exothermic: Energy is released

-Endothermic: Energy is absorbed

-Activation energy: The energy required to get a reaction started

Catalyst: Speeds up the rate of chemical reactions

-Not destroyed in the process

-Lower activation energy Ex. Heat

Enzyme: Biological catalyst→ Primarily found in cells

-Most are proteins

-Speed up reactions by lowering activation energy

-Very specific (Picky with what they’ll build or breakdown)

→One enzyme to one reaction

-Enzymes can be stopped from working

-They’re also picky with the conditions

Denaturing: Destroys the enzyme