BIO 101 - Chapter 2

Professor Mendoza

Matter

Consists of one or more elements organized into atoms and molecules

Element

A substance that cannot be broken down any further by chemical means

What are the six main elements living forms are composed of?

\-Carbon

\-Hydrogen

\-Oxygen

\-Nitrogen

\-Phosphorus

\-Sulfur

What does the atomic number indicate?

How many protons the element has

How do you determine the number of neutrons in an element?

atomic mass - atomic number

Isotope

A form of an element containing a different number of neutrons

Covalent Bonds

When atoms share electrons. (nonmetal+metal)

Ionic Bond

When electrons are transferred (nonmetal+metal)

Electronegativity

Moves low - to high, from left to right on a periodic table (Slide 24 ) Second ppt

Atomic radius

Increases moving from high to low on a periodic table (Slide 24 ) Second ppt

Cohesion

The tendency of like molecules to stick to one another.

Adhesion

The tendency of dissimilar particles to stick to one another.

Solvent

A substance (typically liquid) capable of dissolving another substance.

Factors contributing to high surface tension of water

\-hydrogen bonding

\-polar covalent bonds

\-cohesion

Acidic solutions

 have a low pH and a high H+ concentration.

Basic solutions

have a high pH and a low H+ concentration. _____have more OH− ions than H+ ions.

Organic Molecule

A molecule that contains both carbon and hydrogen (Ex. Methane)

4 Organic Molecule Categories

* Carbohydrates
* Proteins
* Nucleic Acids
* Lipids

Monomers

A single unit of an organic molecule.

Polymers

Multiple monomers join to form a polymer

Dehydration synthesis

What joins monomers into polymers/ What links fatty acids to glycerol

Hydrolysis

What breaks polymers into monomers./ What separates fatty acids from glycerol

Monosaccharides

The monomers that make up carbohydrates. Ex. Ribose, Glucose, Fructose

Disaccharides

Two monosaccharides join together to form_______. Ex. Sucrose

Polysaccharides

Long chains of carbohydrates Ex. Cellulose, Starch, Glycogen

Amino Acids

The monomers for protein (20 different ones) each have their own chemical and physical properties

Dipeptide

Two proteins monomers (amino acids) form this.

Polypeptide

A chain of protein monomers (amino acids) form this.

The function of a protein is dependent on?

Its shape or tertiary structure

Primary structure

Amino acid sequence of a polypeptide (sequence)

Secondary structure

Localized areas of coils, sheets, and loops within a polypeptide (substructure)

Tertiary Structure

Overall shape of one polypeptide

Quaternary Structure

Overall protein shape, arising from interaction between the multiple polypeptides that make up the functional protein. Only proteins with multiple polypeptides have quaternary structure

Nucleotides

The monomers of nucleic acids

5 different types of nucleotides

* Adenine (A)
* Cytosine (C)
* Guanine (G)
* Thymine (T)
* Uracil (U)

What are the classes of lipids?

* Triglycerides
* Steroids

Triglycerides

Energy rich substances used for long term energy storage. Ex. Fats and Oils

Steroids

Group of lipids with a 4-ring Structure of carbon atoms. (Not much info in the ppt)

How are Triglycerides formed?

Through covalent bonds attaching three fatty acid molecules to a glycerol molecule

Saturated Fatty acids

When the carbon in a fatty acid is bonded to four other atoms, the fatty acid holds a straight shape Ex. Butter

Unsaturated Fatty Acids

When the carbon atom in a fatty acid contains at least one double bound, the fatty acid holds a bent shape. The bends prevent them from solidifying Ex. Oils

Cholesterol

\-Used to regulate the fluidity of animal cell membranes

\-Used to synthesize many sex hormones

Types of Steroids

\-Cholesterol

\-Testosterone