bio&160 chapter 2

Matter

any material that takes up space and is made up of atoms.

Energy

the ability to do work

What does work mean in this context?

The ability to move matter

Element

A pure substance that cannot be broken down.

What is matter made up of?

One or more elements.

How is the periodic table organized?

It lists the elements according to their properties

What is the composition of atoms?

Protons and neutrons form together to make up the nucleus, and a cloud of electrons surround the nucleus.

What charge is protons, neutrons, and electrons?

Protons are positive, neutrons are neutral, and electrons are negative.

What does the atomic number mean?

The number of protons in the nucleus

Where is the atomic number located?

Above each elements symbol

What happens when the number of protons equals the number of electrons?

The atom is neutral

Ion

an atom or group of atoms that has gained or lost electrons that has a final negative or positive charge.

What do ions do?

Participate in many biological processes, forms IONIC BONDS

Mass number

total number of protons and neutrons in the nucleus

Isotope

any forms of an element, with each having a different number of neutrons in the nucleus

Atomic weight

the average mass of all atoms in an element

What 4 elements do organisms require in the largest amounts?

Carbon, hydrogen, oxygen, and nitrogen. Remember** C.H.O.N

Molecule

two or more chemically joined together atoms

Compound

A molecule composed of two or more different elements

Orbitals

where particular electrons would likely be as they circle the nucleus

Energy shells

group of electron orbitals that have the same amounts of energy levels

Valence shell

The outermost shell of an atom with electrons that interact with other atoms to form chemical bonds (by sharing, gaining, or losing electrons)

Electronegativity

an atom's tendency to attract electrons

Chemical bonds

attractive forces that hold atoms together

What are the 3 important chemical bonds in biology?

Ionic bonds, Covalent bonds, Hydrogen bonds

Ionic bond

the attraction between oppositely charged ions; positive ions + negative ions = ionic bond!

Covalent bond

bond where two atoms share electrons

What are the two types of covalent bonds?

Polar and nonpolar

Polar covalent bonds

Electrons are shared unequally in the bond

Nonpolar covalent bonds

Electrons are shared equally in the bond

Hydrogen bond

An atom with a partial negative charge attracts a hydrogen atom with a partial positive charge. GET BACK TO THIS

What is essential to all organisms?

Water!!!

What are the properties of water?

Cohesion and adhesion, its ability to dissolve substances, it regulates temperatures, it expands as it freezes, and is both a chemical reactant and product

Cohesion

The tendency of water molecules to stick together.

Adhesion

The attraction of water molecules to substances other than water; the tendency to form hydrogen bonds with substances other than water.

Give an example of cohesion and adhesion

Water moving from a plants roots to its leaves

Solvent

a chemical that dissolves other substances

Solute

a chemical that dissolves

Solution

a mixture of a chemical dissolved in another

Explain solvents, solutes, and solution in relation to one another

solvents dissolve solutes which create the solution.

Hydrophilic

attracted to water; “water loving”

Hydrophobic

repelled by water; “water-fearing”

Give an example of water dissolving substances

salt dissolves in water.

Explain what the solvent, solute, and solution is with salt and water.

The solvent is water, the solute is salt, and the solution is saltwater!

How does water regulate temperature?

Hydrogen bonds in water keep from changing temperatures quickly, sweat cools the body as water evaporates from the skin

Evaporation

conversion of a liquid into a vapor (gas)

Give an example of how water regulates temperature

coastal climates being milder than inland climates

Give an example of water expanding as it freezes.

Ice floating on a lakes surface

Chemical reaction

when bonds break down and new bonds are formed

Reactants

starting material in a chemical reaction

Product

the result of a chemical reaction

What happens in a chemical reaction?

reactants swap atoms to form products. As atoms are swapped, chemical bonds are broken, energy is released or used in the reaction,and new chemical bonds form

Give an example of water being a chemical reactant and product.

photosynthesis requires water molecules

Acid

A chemical that releases hydrogen ions into a solution

Base

A chemical that releases hydroxide into a solution or removes hydrogen ions from it; the opposite of acid

Neutral solution

neither acidic nor basic solution

pH

a measurement of how acidic or basic a solution is

How is the pH scale measured?

it ranges from 0 to 14,with 7 being neutral, 14 being extremely basic, and 0 being extremely acidic.

How is correct pH able to be maintained?

cells contain buffers which are pairs of weak acids of bases that resist pH changes

Organic molecules

compounds containing both carbon and hydrogen

Monomers

Building block molecules

Polymers

chains of monomers that are linked together by covalent bonds

What property do proteins, nucleic acids, and some carbohydrates all share with each other?

they are polymers

How are these molecules connected?

Through hydroxyl, carboxyl, amino, and phosphate groups

How are monomers linked into polymers?

through dehydration synthesis

What is the process of dehydration synthesis?

an OH (hydroxyl group) is removed from one molecule and a hydrogen atom is removed from another molecule, and the two removed parts form H2O (water). After the water is removed, a new covalent bond is created.

How to remember dehydration synthesis?

it means building something new by removing water.

Hydrolysis

the exact opposite of dehydration synthesis. It breaks the covalent bonds that are linking the monomers by adding in water, splitting it back into smaller components.

What is the function of carbohydrates?

supplies or stores energy.

What is the chemical structure of carbohydrates?

compounds that contain carbon, hydrogen, and oxygen in a 1

What are the two main groups of carbohydrates?

simple sugars and complex carbohydrates

What are the two categories of simple sugars?

Monosaccharides and disaccharides.

Monosaccharides

a sugar molecule with 5 or 6 carbon atoms. Ex. glucose and fructose

Disaccharide

two monosaccharides joined together by dehydration synthesis.

What is the function of simply sugars?

They provide quick energy

What are complex carbohydrates made up of?

Polysaccharides

What is the function of complex carbohydrates?

they support cells and organisms and story energy

What are polysaccharides and what are they made up of?

Huge molecules consisting of hundreds or thousands of monosaccharide monomers. Ex. cellulose, starch, glycogen.

Protein

a long, folded chain of monomers called amino acids.

What is the chemical structure of amino acids?

A central carbon atom bonded to four other groups, being hydrogen, a carboxyl group, an amino group, and a side chain or R group.

How are amino acids connected?

through dehydration synthesis reactions

What is the covalent bond connecting amino acids called?

peptide bonds

Polypeptide

chains 100+ amino acids that make proteins

When are polypeptides called proteins?

when they fold into functional shapes. Proteins consist of 1+ polypeptide chains.

What is the function of proteins?

They carry out nearly all the work of the cell

How is protein folded?

Into 4 structures--primary, secondary, tertiary, and quaternary.

Denature

modifying protein shape so its functions are destroyed

What are some conditions that can denature a protein?

heat, excessive salt, wrong pH etc.

Nucleic acids

a long polymer consisting of nucleotides. DNA and RNA are nucleic acids.

What is the function of nucleic acids?

They store and transmit genetic information to next generations

Nucleotide

building blocks of nucleic acid. Made up of a phosphate group, nitrogenous base, and a five-carbon sugar

What links together nucleotides?

Dehydration synthesis

DNA

carries genetic information and transmits it from generation to generation

RNA

Lipids

organic compounds that don’t dissolve in water made up of mostly carbon and hydrogen

Triglyceride

a lipid consisting of one glycerol bonded to 3 fatty acids

Fatty acids

long chains that are mainly carbon and hydrogen, bonded to glycerol

Glycerol

a 3 carbon molecule that's the backbone of triglycerides

Saturated fatty acids

fatty acid with all single bonds; solid at room temp; looks straight; the worse for u fatty acid

Unsaturated fatty acids

fatty acid with at least one double bond between carbon atoms; liquid at room temp,has a kink, better for you