Life Science Exam 1

Front 1

What are the characteristics of living things?

Back 1

(1) Highly Organized = both large and small organisms are complex and organized.
(2) Maintain themselves over time = the grow and develop which leads to reproduction.
(3) Take in, transform, and utilize energy = Energy is the ability to do work
(4) Maintain homeostasis = the optimum range that a cell or organism works best.
(5) Living things respond to stimuli = both from within and from outside sources.
(6) Able to adapt to environmental change = this may be quick or slow. There are limits to how much change they can withstand.

Front 2

1st Law of Thermodynamics

Back 2

Energy can be transform from one form to another but is never destroyed.

Front 3

2nd Law of Thermodynamics

Back 3

All processes in the universe and the utilitzation (entropy) of that energy runs to disorder. Not all sources of energy are usable. Ex. The number of cells in humans do not change, the number does not grow, thus they work against the 2nd law as long as possible.

Front 4

Protons

Back 4

Postively charged particles found in the nucleus of the atom. The number of protons = the atomic number of an atom.

Front 5

Neutrons

Back 5

Particles with no charge that are found in the nuclues of the atom.

Front 6

Electrons

Back 6

Negatively charged particles in an atom. For every positive charge, there must be an equal negative charge. # of protons = # of electrons.

Front 7

Atomic Weight

Back 7

the sum of the protons and neutrons.

Front 8

Isotopes

Back 8

When there is a variable # of neutrons. Different isotopes of an element have varying numbers of neutrons but the same number of protons.

Front 9

Energy Levels or Orbitals

Back 9

an orbital is the volume of space in which an electron can be found.
1. The first orbital is a sphere around the nucleus capable of holding 2 electrons.
2. The 2nd orbital is a sphere and 3 dumbbell shaped spaces that can hold up to 8 electrons.
3. The third can also hold up to 8.
Quantum is the energy required to move electrons from 1 orbital to another. When electrons move down an orbital, they release energy. The more room there are for more electrons the more reactive the atom is. Atoms like their outer most energy level to be filled. Bonds are the attraction of atoms that can fill the outer most energy levels.

Front 10

Oxidation/Reduction Reactions

Back 10

This is an energy transformation reaction. Elements that give away electrons are oxidized. Elements that gain electrons are reduced, they become more negative. Hydrogens are often involved because it has only 1 electron. Thus these reactions usually result in a redistribution of hydrogen molecules.

Front 11

6 Most Important Elements

Back 11

1. Carbon: 4 electrons
2. Hydrogen: 1 electron
3. Oxygen: 5 electrons
4. Nitrogen: 6 electrons
5. Phosphorus: 5 electrons
6. Sulfur: 6 electrons

Front 12

Ionic Bonds

Back 12

When one element is giving up electrons. (Think Sodium and chlorine, Na+CL-)

Front 13

Covalent Bonds

Back 13

When elements share electrons. (Think H20) When 2 or more atoms combine in a covalent reaction, the result is a molecule.

Front 14

Polar Covalent Bonds

Back 14

A bond in which elements share electrons but each end of the molecule has a charge. In an H2O molecule the H side is more positive and the O side is more negative.

Front 15

Organic Molecules

Back 15

Organic molecules have a lot of carbon in them. Ex. Carbohydrates, Lipids, Nucleic Acis, and Proteins

Front 16

Condensation Reactions

Back 16

When macromolecules are combined. (ex. 2 monosaccharides) In this instance water is given off, thus condensation reaction.

Front 17

Hydrolysis Reaction

Back 17

When a macromolecule is split into two and water is required to complete the reaction. (ex. 1 disaccharide splitting into 2 monosaccharides.)

Front 18

Sugars

Back 18

They are carbohydrates. The bonds between the rings represent a source of energy for saccharides.
1. Monosaccharides: simple sugars and the building blocks of carbohydrates. It is a ring of 6 carbons. Can be converted into ATP = energy to do work. (ex. glucose. In order to turn glucose into ATP we need to oxidize glucose. 1 string of glucose can get you 38-36 ATP.)
2. Disaccharides: have 2 carbon rings and are more for transport. Disaccharides are split into monosaccharides to produce ATP. (ex. sucrose and lactose)
3. Polysaccharides: Many carbon rings. (exs. glycogen = stored in the liver when they are not needed, starch = common in plants, cellulose = cell wall in plants, chitin = exoskeleton.)

Front 19

Amino Acids, -COOH with N

Back 19

All amino acids have an amino group (NH2) and a carboxyl group (CO2H)attached to the central carbon. Amino Acids are the building blocks of proteins. There are 20 types of amino acids which produce an infinite number of proteins because a protein can be any sequence of amino acids.

Front 20

Fatty Acids and Triglycerides

Back 20

The building blocks of lipids are 3 fatty acids and a glycerol molecule (triglyceride). Glycerol = a carboxyl group (CO2) and a H-C-CH2 bond and a carbon chain. There are 3 different types of fatty acid carbon chains. The double and triple bonds in the carbon chain = unsaturated. Single bonds = saturated. The more double and triple bonds, the more energy is released when you break those bonds, giving you more energy.

Front 21

Nucleotides

Back 21

The building blocks for DNA. They consist of (1) a phosphate in the form of a phosphoric acid, (2) a sugar = a 5 carbon ring, ribose for RNA, deoxyribose for DNA, (3) nitrogenous bases = DNA: A, T, G, C RNA: A, U, G, C

Front 22

Carbohydrates

Back 22

They are our most important source of energy. There are minosaccarides, disaccharides, and polysaccharides. We cannot digest complex carbohydrates such as chitin and cellulose. We do eat glycogen and starch.

Front 23

Lipids

Back 23

They are more formally defined as a substance such as a fat, oil or wax that dissolves in alcohol but not in water. They have a 2 fold function: (1) energy, (2) structural. They have a greater # of carbon-hydrogen bonds and less oxygen. They form cholesterol which we need for hormones whihc produce testosterone and estrogen.

Front 24

Proteins

Back 24

A protein is a large polymer of amino acids, composed of one or more polypeptide chains.
Primary Structure: the linear sequence of amino acids
Secondary Structure: the chain is folded at specific points (keratin in hair and nails)
Tertiary Structure: the chain is folded a 2nd time. (actin, muscle cells)
Quaternary structure: the chain is folded again. (hemoglobin)
Some proteins are nezymes which catalyze (enhance) chemical reactions. Glycoproteins act as natural anti-freeze in the body. Structural proteins make up things like hair.

Front 25

Nucleic Acids

Back 25

Their transmission from one generation to the next is the basis of heredity. The two main types, DNA and RNA, are composed of similiar materials but differ in structure and function. Both are long chains of repeating nucleotides. The sequence of purines and pyrimidines (bases) - adenine (A), guanine (G), cytosine (C), and either thymine (T in DNA) or uracil (U in RNA) - in the nucleotides, in groups of three (tiplets, or codons) constitutes the genetic code.