Chapters 1 to 4 Review BIO 141

What do scientists use?

Scientific method

Chemicals…

Break down into compounds and elements

4 properties of water.

Polar molecule, temperature moderation, universal solvent, cohesive behavior

elements may be toxic but

Their compounds might not be

What compound makes up most of your body

Water

Chemical bonds

Covalent, Ionic, Hydrogen

Covalent Bond

Strongest bond, shares a pair of valence electrons by two atoms

Ionic bonds

Ions are attracted to each other by opposite charges

Hydrogen bonding

2 elements are sharing a hydrogen

Kinetic energy

Movement of molecules

3rd most common element in your body

Hydrogen

Most common element in body

Oxygen

2nd most common element in the body

Carbon

Molecule shape matters because

You can co-op molecules for drugs, a molecule of the same shape but different property can bind to receptors and mimic the same reactions

Temperature

Measure of movement of molecules

Heat

Total amount of kinetic energy

Specific heat

Amount of heat that must be absorbed/lost to change temp by 1cal/g/Celcius

Why is specific heat?

Higher heat keeps bonding tighter which is harder to tear apart

How does water climb up a tree

Evaporation by H20 because gas rises and the cohesive properties of the hydrogen bonds connect as they go up the tree

Surface tension

how hard it is to break the hydrogen bonds that create tension

7 chemical groups in biological processes

Hydroxyl, Carbonyl, Carboxyl, Amino, Sulfhydryl, Phosphate, Methyl

3 isomers

Structural, Cistrans, Enantiomers

Which enanitiomers are created naturally

L-Enantiomers

what are enantiomers

mirror images of each other

Element

substance that cannot be broken down into other substances

compound

made of two or more elements

atom

smallest unit of matter that retains properties of an element and is made of protons, neutrons, and electrons

Proton

positive charge

Neutrons

no charge

electrons

negative charge, differ in potential energy and energy level/shell

Energy

capacity to cause change

potential energy

energy that has location or structure

Electrons in an atom

They have valence electrons

Describe energy levels of electrons

There are 3 shells. The first shell is the lowest energy potential and the third is the highest energy potential. Electrons transfer up each level when energy is absorbed, but when energy is lost, they drop down shells toward the nucleus of the atom

Valence electrons

outermost layer of the atom, which determines the atom's chemical behavior. Atoms with full shells are chemically inert.

Van Der Waals Interactions

attractions between molecules as a result of electrons collecting in parts of molecules or atoms

Why is water life?

It is the biological medium of our planet, all living organisms require water, surrounds most cells, 70-95% of cells are water, abundance of water is required for life

What is special about a polar molecule?

Allows for hydrogen bonding

4 properties of Water

Cohesive behavior, moderates temperature, expansion upon freezing, versatile solvent

Cohesion

Hydrogen bond to hold water molecules and helps the transport of water

adhesion

Attraction between different substances

Surface tension

Measure of how hard it is to break surface of liquid

How does water moderate temperature

Through kinetic energy and temperature

Kinetic energy

energy of motion

Temperature

measures the intensity of heat due to average kinetic energy molecules

Heat

measures total amount of kinetic energy due to molecular motion

Why does water have high specific heat

Minimizes temperate fluctuations and hydrogen bonding, 1cal/g/Celsius

Specific heat

Amount of heat that must be absorbed or lost for 1g of substance to change its temperature by 1 degree celsius

Evaporative cooling

When liquid turns to gas and helps stabilize temperatures in bodies of water

Evaporation

liquid to gas

Heat of vaporiztaoin

liquid that absorbs

Ice Floats why?

Hydrogen bonds make ice less dense

Solution

a liquid that is homogenous mixture

solvent

dissolving agent

solute

substance dissolved

Aqueous solution

solution where solvent is water

Why is water a versatile solvent

Because of its polarity and when an ionic compound is dissolved in water, each ion is surrounded by a sphere of water molecules called a hydration shell. Water can dissolved compounds made of nonionic polar molecules. Larger polar molecules, such as proteins can dissolved in water if they have ionic and polar regions

Polarity

allows for easy hydrogen bonding

Hydration shell

when water molecules orient around a dissolved ion or polar molecule due to water’s polarity

Acidic and basic conditions affect living organisms

Hydrogen bond between two water molecules can shift from one to another to become hydrogen ions, hydronium ions, and hydroxide ions

Hydrogen ion

hydrogen atom leaves its electron behind and is transferred as a proton

Hydronium ion

H2O molecule with the extra hydrogen proton from H2O molecule

Hydroxide ion

H2O molecule that lost hydrogen proton

Acid

any substance that increases the H+ concentration of a solution

Base

any substance that reduce the H+ concentration of a solution

Organic

Consisting of carbon and the molecular diversity of life being very simple to complex

Carbon - Backbone of life

Living organisms consist of mostly carbon-based compounds. Carbon is unparalleled in its ability to form large, complex, and diverse molecules. Proteins, DNA, carbohydrates, and other molecules that distinguish living matter are all composed of carbon compounds.

Stanley Miller

Classic experiment demonstrated the abiotic synthesis of organic compounds. Supports idea that abiotic synthesis of organic compounds could have been a stage in the origin of life

• perhaps near volcanoes

Carbon bond formations

four valence electrons, complex molecules are possible, tetrahedral shape, double bond, compatibility with many different elements

Diverse Molecules

Most frequent partners of Carbon

hydrogen, oxygen nitrogen

Carbon atoms can..

partner with atoms other than hydrogen

Carbon bonding examples

Hydrocarbons

Hydrocarbons, many organic molecules have hydrocarbon components. Can undergo reactions that release a large amount of energy

Hydrocarbons definition

Organic molecules consisting of only carbon and hydrogen

Isomers

Compounds with the same molecular formula but different structures and properties

Structural, Cis-trans, Enantiomers

Structural isomers

have different covalent arrangements of their atoms

Cis-trans isomers

have same covalent bonds but differ in spatial arrangements

Enantiomers

Isomers that are mirror images of each other

Hydroxyl

Alcohols, written as —OH, is polar, can form hydrogen bonds, helps dissolve organic compounds

Carbonyl

If the Carbonyl group is within a carbon skeleton: its a ketone

If the carbonyl group is at the end of a carbon skeleton: its a aldehyde

Carboxyl

Carboxyl acids/Organic compounds

• Acts as an acid, can donate H+ because of the covalent bond between oxygen and hydrogen is polar

Amino

Amines structure, acts as a base, can pick up H+ from solution

Sulfhydryl

Thiols structure, two sulfhydryl groups can form covalent bond and “Cross-link” protein structure.

Phosphate

Organic phosphate structure, contributes negative charge to molecule. Molecules containing phosphate groups have the potential to react with water, releasing energy

Methyl

methylated compound structure that affects expression of genes in male/female sex hormones