BIOL1610 Exam 1

Characteristics of Life

1. Reproduction
2. Growth & Development
3. Energy Use
4. Order
5. Regulation
6. Response to Environment
7. Evolution

Smallest unit that displays characteristics of life:

Cell

Unity of Life

Caused by a common ancestor (DNA, cell structure)

Diversity of Life

Caused by natural selection (adaptation, speciation)

Emergent Properties

interactions between individual components produce new functions not present in previous level

Biosphere

encompasses all the ecosystems on Earth

Ecosystems

includes living organisms and the environment that they live in

Communities

Sum of populations inhabiting an area

Population

All the individuals of a species living in a specific area

Organism

Individual living entities

Organs

Collections of tissues grouped together performing a common function

Tissues

Groups of similar cells carrying out similar or related functions

Cells

The smallest fundamental unit of structure and function in living organisms

Organelles

Small structures that exist within cells

Molecules

The smallest particle of a specific compound that retains the chemical properties of that compound

Basic Process of Science

1. Observations and questions
2. Generate a hypothesis
3. Make a testable prediction
4. Test w/ experimentation
5. Draw conclusions, revise, repeat

A hypothesis must achieve what two goals

Testable and Falsifiable

Difference between a Scientific Theory and a Hypothesis

A scientific theory is broad in scope while a hypothesis is more specific

Experimental Group

The group that receives the experimental procedure

Control Group

Treated identically to the experimental group, but are not exposed to the treatment

Independent Variable

The variable that is manipulated by scientists, plotted on the x-axis

Dependent Variable

The variable that responds to the manipulation, plotted on the y-axis

Chemicals _____ through an ecosystem

cycles

Energy _____ through an ecosystem

flows

In Chemical Reactions

Chemical bonds are broken and reformed, leading to new arrangements of atoms.

Reactants

The starting molecules in a chemical reaction

Products

The final molecules of a chemical reaction

Anion

a negatively charged ion

Cation

a positively charged ion

Why is an anion negatively charged

Anions have more electrons than protons. Electrons have a negative charge making the anion negatively charged as well

Cations have more _____ than electrons

Protons

What determines the chemical behavior of an atom

the number of electrons in the atom’s valence shell

Isotopes

Two or more forms of an element that all have the same amount of protons in the nucleus, but differ in the amount of neutrons

4 Major Elements within the Human Body

1. Carbon
2. Hydrogen
3. Oxygen


1. Nitrogen

In the atom’s first electron shell it can hold _____ electrons. In all the other shell it can hold how many electrons

2, 8

Covalent Bonds

Ionic Bonds

can form if two atoms are so unequal in their attraction for valence electrons that one atom strips an electron completely from the other

Hydrogen Bonds

form when a hydrogen atom that is already cova

Srongest to Weakest Bonds

Electronegativity

The attraction of a particul

Nonpolar Covalent Bonds

The electrons are shared equally between

Polar Covalent Bonds

Occur when one atom is bonded to a more electronegative atom, and the electrons are not shared equally

Hydrophobic

not soluble in water

Hydrophillic

Soluble in water

Cohesion

hydrogen bonds holding water together

Adhesion

water molecules holding onto another substance

Specific Heat

The amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1 degree C

Why does ice float

As a result of hydrogen bonding, the bonds keep molecules far enough apart to make ice about 10% less dense than water

What is the universal solvent

Water, due to its polarity

pH of 0-6.9

Acidic, more H+ ions in solution

pH of 7.1-14

Basic, more OH- in a solution

pH of pure water @ 25C? Concentration of H+ and OH- atoms?

7, 10^-7 M (equal in concentration)

Functional Groups

help determine the properties of a compound and in what chemical reactions it participates in

4 Main Macromolecules

1. Carbohydrates
2. Lipids
3. Proteins


1. Nucleic Acids

Polymer

a long chain-like molecule consisting of many similar or identical monomers linked by covalent bonds

Monomer

smaller molecules that serve as the building blocks of polymers

What are the monomers of these polymers?


1. Carbohydrates
2. Proteins
3. Nucleic Acids

1. Monosaccharides
2. Amino Acids
3. Nucleotides

Dehydration Reaction

creates a bond between two monomers by removing a water molecule, creates a covalent bond between the two monomers

Hydrolysis Reaction

Breaks bond between two monomers by adding a water molecule

Which polymers have sugars? Phosphorous? Nitrogen?

Carbohydrates & Nucleic Acids, Nucleic Acids & Phospholipids, Proteins & Nucleic Acids

Are lipids considered polymers?

No, they are not comprised of repeating subunits

Starch

Energy storage in plants

Glycogen

Energy storage in animals (liver)

Cellulose

Structural support of plants, non-digestible dietary fiber, most abundant compound on Earth

Chitin

Structural support of insects (exoskeleton) and fungi (cell wall)

Lipids

All hydrophobic, non-polar, mostly C’s and H’s

Fats (triglycerides)

Long term energy storage

Phospholipids

cell membrane

Steroids

signaling and cell membrane

Typical Triglyceride Molecule

Single glycerol molecule joined with 3 fatty acids

Saturated Fats

* maximum # of hydrogen atoms (no double bonds)
* often solid at room temperature
* all three fatty acid tails are “saturated” with hydrogens

Unsaturated Fats

* Fewer than the maximum # of hydrogen atoms (one or more cis-double bonds
* often liquid at room temperature

Trans Fats

Hydrogenation of plant oils produces trans double bonds (opposite side, straight chain

Phospholipid Structure

Glycerol, 2 fatty acid tails, and phosphate group instead of a 3rd fatty acid. The head is polar and hydrophilic. The tail is nonpolar and hydrophobic.

Phospholipids form

membranes of all living s

Cholesterol

component in animal cell membranes

Hormones

Regulate sexual development, maturation, sex cell production, stress (cortisol). Made from cholesterol

Proteins

building blocks of life, made of amino acid monomers linked by peptide bonds

What are the functions of proteins

* enzymes
* storage
* contractile
* transport
* receptor
* hormone
* defensive
* structural

How many amino acids are there? What makes them differ?

20 amino acids, R group in each amino acid

Four levels of protein structure

1. Primary Structure: Polypeptide chain of amino acids (built directly from DNA)
2. Secondary: Hydrogen Bonds form between the amino acid backbones, making an alpha helix or a beta helix sheets
3. Tertiary: Bonds between the side chains determine the tertiary (folded) structure of the protein
4. Multiple polypeptides aggregate into a larger unit (not all proteins)

Three main groups that form the structure of an amino acid

1. amino group
2. carboxl group
3. r group

Denaturation

when environmental conditions are not right, the protein will unfold. May reform when environment returns to normal. Results in the loss of its biological activity

Enzymes

accelerate chemical reactions (catalysts)

Hormones

coordinate activities of the endocrine system

Nucleic Acids

store and transfer genetic information, form the basis of inheritance.

Nucleotides

the building blocks of nucleic acids

A nucleotide is made up of

1. A phosphate group
2. a sugar
3. a nitrogenous base

What are the 5 nitrogen bases?

1. Adenine
2. Guanine
3. Cytosine
4. Thymine
5. Uracil

Central Dogma

the flow of genetic information from DNA to RNA to Proteins

Why are DNA strands said to be antiparallel?

The two strands are said to be antiparallel because they run in opposite 5’ to 3’ directions from each other

The two domains of prokaryotic cells

1. Bacteria
2. Archaea

Ribosomes

make proteins

Plasma Membrane

separate the inside of the cell vs. outside

DNA (chromosomes)

stores genetic information

Cytosol

moves material around cell and contains dissolved nutrients

Cell wall

protects/maintains cell shape

Chloroplasts

perform photosynthesis

Central Vacuole

stores water, ions, and turgor pressure

Plasmodesmata

similar to gap junctions in animals, allow communication across plant cells