Unit 1 : Chemistry Of Life

Hypothesis

A testable prediction based on observations

Theory

Summarizes a group of hypotheses

Experimental Group

A group in an experiment that receives the treatment of the variable being tested

Scientific Law

A statement of fact (mathematical formula)

Control Group

A group in an experiment that does not receive any of the treatment

Deductive Reasoning

Specific results are derived from general premises

Inductive Reasoning

Derive generalizations based on a large number of specific observations

Constants

Things that do not change throughout the experiment, they stay constant

Alternative Hypothesis

A hypothesis that may be supported or proven by data

Null Hypothesis

A hypothesis which the researcher tries to disprove, reject, or nullify a question

Independent Variable

The one factor that is changed by the person doing the experiment

Dependent Variable

The factor which is measured in the experiment

Central Tendencies

The center of the distribution can be described by the mean, median, or mode

Mean

The average of the data set

Median

The middle number in a range of data points

Mode

The value that appears most often in a data set

Variability

the measure of how far a data set diverges from the central tendency

Range

The difference between the largest and smallest values

Standard Deviation

A measure of how spread out the data is from the mean

Standard Error of the Mean

Used to determine the precision of and confidence in the mean value

Standard Error of the Mean formula

See image

Data

recorded observations

Qualitative

observations with senses (think qualities)

Quantitative

measured using instruments (think numerical)

Positive Control Group

Group is not exposed to the experimental treatment or independent variable, but IS exposed to a treatment that is known to produce the expected result

Negative Control Group

Group is not exposed to any treatment or exposed to a treatment that is known to have NO effect

Low standard deviation

Means the data is closer to the mean ; independent variable is likely causing changes

High standard deviation

Means the data is farther from the mean (more spread out) ; factors other than the independent variable are likely causing changes

Standard deviation formula

See image

If the error bars overlap

the difference is not significant

If the error bars do not overlap

the difference may be significant

Essential Elements

of the 92 naturally occurring elements 20-25% are essential to survive and reproduce (CHOPN) make up 96% of all living matter

CHOPN

carbon, hydrogen, phosphorus, and nitrogen

Trace Elements

of the 92 naturally occurring elements, these are required by an organism in very small quantities

Bohr Model

shows electrons orbiting the nucleus of an atom

Lewis Dot Model

simplified bohr diagrams

Cation

positively charged ion

Anion

negatively charged ion

Polarity

unequal sharing of electrons makes a polar molecule

High specific heat

H2O resists changes in temperature

Evaporative Cooling

water has a high heat of vaporization

Water's Special Property of Density

as water solidifies it expands and becomes less dense

Matter

Anything that takes up space and has mass

Element

A substance that cannot be broken down into other substances by chemical reactions

Compound

A substance consisting of two or more different elements combined in a fixed ratio

Octet Rule

Elements will gain, lose, or share electrons to complete their valence shell and become stable

Capillary Action

The upward movement of water due the the forces of cohesion, adhesion, and surface tension

Chemical Bonds

An attraction between two atoms, resulting from the sharing or transferring of valence electrons

Hydrogen Bonds

The partially positive hydrogen atom in one polar covalent molecule will be attracted to an electronegative atom in another polar covalent molecule

Covalent Bonds

When two or more atoms share electrons (usually between 2 nonmetals)

Ionic Bonds

The attraction between oppositely charged atoms ; there is a transfer of electrons

Cohesion

attraction of molecules for other molecules of the same kind

Electronegativity

The measure of an atom's ability to attract electrons

Adhesion

The clinging of one molecule to a different molecule

Atomic Mass

The number of protons plus neutrons averaged over all isotopes of an element

Solute

Substance that is dissolved

Solution

Homogenous mix of two or more substances

Solvent

Dissolving agent in a solution

Valence Electrons

The electrons in the outermost shell of an atom.

Molecule

A group of atoms bonded together, representing the smallest unit of a chemical compound that can take part in a chemical reaction

Functional Groups

Chemical groups attached to the carbon skeleton that participate in chemical reactions

Organic Chemistry

The study of compounds with covalently bonded carbon

Organic Compounds

Compounds that contain carbon and hydrogen

Hydrocarbons

Organic molecules consisting only of carbon and hydrogen

ATP

Adenosine triphosphate is an organic compound that provides energy to drive and support many processes in living cells

Macromolecule

A very large molecule (proteins, carbohydrates, nucleic acid, and lipids) built up from smaller chemical structures

Dehydration Reaction

Bonds two monomers with the loss of H2O

Hydrolysis Reaction

Breaks down the bonds in a polymer by adding H2O

Monomers

The repeating units that make up polymers

Polymers

Chain like macromolecules of similar or identical repeating units that are covalently bonded together

Storage Polysaccharide

Stores glucose ; starch and glycogen

Structural Polysaccharides

Cellulose and chitin

Chitin

forms exoskeleton of arthropods

Carbohydrate

A macromolecule that include sugars and polymers of sugars

What does a carbohydrate contain

a carbonyl group and many hydroxyl groups

What is a carbohydrate comprised of

carbon, hydrogen and oxygen

Monosaccharide

Simple sugars ; monomers of carbohydrates

Disaccharide

Two monosaccharides joined together by covalent bonds

Polysaccharide

Polymer with many sugars (monosaccharides) joined via dehydration reactions

Glycosidic linkage

A covalent bond that links two monosaccharides together

Starch

How plants store glucose ; a polymer of glucose monomers

Cellulose

A tough substance that forms plant cell walls ; a structural polysaccharide

Glycogen

How animals store glucose ; a polymer of glucose

Amino Acids

Molecules that have an amino group and a carboxyl group ; a macromolecule

Polypeptide

Many amino acids linked by peptide bonds

Hydrophobic

Attract away from water

Hydrophilic

Attract towards water

Monomer of Carbohydrates

monosaccharides

Polymers of Carbohydrates

disaccharides and polysaccharides

Nonpolar side chain

hydrophobic

Polar side chain

hydrophilic

Charged/ionic side chain

hydrophilic/acidic/basic

Formation of Peptide Bonds

the carboxyl group of one amino acid must be positioned next to the amino group of another amino acid

Function of the Protein - Antibody

help protect the body from disease

Function of the Protein - Enzyme

carry out chemical reactions or assist in creating new molecules

Function of the Protein - Messenger

transmit signals (hormones)

Function of the Protein - Structural

provide structure and support

Function of the Protein - Transport/Storage

bind to and carry small atoms and molecules through the body

Protein

Molecule consisting of polypeptides (polymers of amino acids) folded into a 3D shape ; comprised of carbon, hydrogen, oxygen, nitrogen, and sulfur ; a macromolecule

Primary Structure

Linear chain of amino acids ; determined via genes ; dictates secondary and tertiary forms