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Biology Exam 1
Scientific Method,Chemical Bonds, Water, Carbon, Biomolecules, Cell & Membrane Structure
105
Biology
Undergraduate 1
03/03/2009

Additional Biology Flashcards

 


 

Cards

Term

 

Properties that distinguish living organisms from the non-living, inorganic world

 

Definition

 

·         Order

·         Regulation, homeostasis

·         Energy processing

·         Evolutionary adaptation

·         Growth and development

·         Response to the environment

·         Reproduction

Term

 

 What, fundamentally, do we mean by this thing called science?

 

 

Definition

 

·         “to know”

·         Way of trying to learn how the physical world works

·         Reality based

·         Systematized, methods

·         Search for explanation and information

Term

 

The Scientific Method

Definition

The process of scientific inquiry

1)      observations

2)      questions

3)      formulate testable hypothesis

4)      make a prediction (if…then)

5)      test prediction (further observations and experiments)

6)      results (either support or falsify hypothesis)

      can never provide final absolute proof

 

 

Term

 

A well designed scientific experiment has...

Definition

 

·         Adequate controls, investigates a single variable at a time, large sample sizes, and is replicated, or the experiment is repeated to be sure the results are reproducible from trial to trial.

 

 

Term

 

                                                 Proton

 

 

Definition

 

·         Subatomic particle with a single, positive, electrical charge found in the nucleus of an atom.

·         # of protons = characteristic of an element, same as # of electrons

·         Mass à heavy, about 1.7 x 10^-24

·         Charge à +1 (electrically charged)

Term

 

Neutron

Definition

 

·         Subatomic particle having no electrical charge found in the nucleus of an atom.

·         Mass à heavy, 1.7 x 10^ -24

·         Charge à 0 (electrically neutral)

 

 

Term

 

Electron

Definition

 

·         Subatomic particle with single negative electrical charge. One or more electrons move around the nucleus of an atom.

·         # of electrons = # of protons

·         Mass = light, 1/2000 that of a neutron or proton

·         Charge = -1 (electrically charged)

 

 

Term

 

 

Element

Definition

 

 

·         Simplest kind of matter that can exist, any substance that cannot be broken down to any other substance by chemical reactions.

Ex. Oxygen, Carbon, Iron

 

 

Term

 

 

Mass Number

Definition

 

 

Sum of the number of protons and neutrons in an atom’s nucleus. 

Term

 

 

Atomic Number

Definition

 

 

The number of protons in the nucleus of an atom, unique for each element and designated by a subscript to the left of the elemental symbol.  

Term

 

 

Isotopes

Definition

 

 

·         One of several atomic forms of an element, each with the same number of protons but a different number of neutrons, thus differing in atomic mass.

·         Unstable = gives off energy as radioactivity.

 

 

Term

 

 

Electron Shells

Definition

 

 

·         correspond to energy levels

·         the outermost, or valence shell, determines the tendency of an element to form chemical    bonds.

·         An energy level of electrons at a characteristic average distance from the nucleus of an atom.

 

 

Term

 

 

Compound

Definition

 

 

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

Term

 

 

Molecule

Definition

 

 

2 or more atoms held together by covalent bonds.

 

 

Term

 

 

Atom

Definition

 

 

the smallest unit of matter that retains the properties of an element. 

Term

 

 

Nucleus

Definition

 

 

 

(1) an atom’s central core, containing protons and neutrons. (2) the chromosome-containing organelle of a eukaryotic cell. (3) a cluster of neutrons.

 

Term

 

 

Ion

Definition

 

  an atom or group of atoms that has gained or lost one or more electrons, thus acquiring a charge.

Term

 

Cation

Definition

 

 

a positively charged ion

Term

 

 

Anion

Definition

 

 

a negatively charged ion

Term

 

 

Chemical Bond

Definition

 

 

An attraction between two atoms, resulting from a sharing of outer-shell electrons or the presence of opposite charges on the atoms. The bonded atoms gain complete outer electron shells.  

Term

 

 

Polar Covalent Bond

Definition

 

A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive.

·         (LOOK FOR O & N!)

·         HYDROPHILIC

 

 

Term

 

 

Non Polar Covalent Bond

Definition

 

 

electrons are shared equally between two atoms of similar electronegativity.

·         HYDROPHOBIC

 

Term

 

 

Hydrogen Bond

Definition

 

weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule.

 

 

Term

 

 

Covalent Bond

Definition

 

 

a sharing arrangement

Term

 

 

Ionic Bond

Definition

 

 

resulting from the attraction between oppositely charge ions.

·         WEAK in water, water soluble.

 

 

Term

 

 

Cohesion 

Definition

 

 

 

the binding together of like molecules often by hydrogen bonds.the way in which water beads up on a waxy surface.  

Term
Adhesion
Definition
the attraction between different kinds of molecules.
Term

 

properties of water

Definition

 

high capacity for temperature moderation(due to high specific heat)

 

high capacity for evaporative cooling

 

ice floats b/c water is less dense as a solid

Term

 

The properties of water as a solvent

Definition

 

good solvent for POLAR solutes

 

"universal solvent" 

 

BAD solvent for NONPOLAR solutes such as oils

 

water molecules have greater attraction for each other

Term

 

 

 

Acid

Definition

 

compound that adds hydrogen ions when dissolved in water (H+) increses ion concentration of a solution.

Term

 

 

Base

Definition

 

reduces hydrogen ion concentration of a solution

Term

 

 

pH scale

Definition

 

 

0 = Very Acidic

7= Neutral

14 = Basic

Term

 

 

Buffer

Definition

 

a substance that consists of acid and base forms in a solution that minimizes changes in pH when extraneous acids or bases are added to the solution 

Term

 

Structural Isomers

Definition

 

have same molecular formula but differ in the covalent arrangements of their atoms

Term

 

 

geometric isomers 

Definition

 

one of several compounds that have the same molecular formula and covalent arrangement but differ in the spatial arrangements of their atoms owing to the inflexibility of double bonds. 

Term

 

Enantiomers

Definition

 

 

one of two compounds that are mirror images of each other.

 

 

Term

 

functional groups

Definition

 

 

reactive groups of atoms that confer certain chemical properties. 

Term

 

Hyrdroxyl Group

Definition

  a.       Structure: (-OH) a hydrogen atom is bonded to an oxygen atom.

b.      Compound: Alcohols (usually names ending in –ol)

c.       Functional Properties:

                                                              i.      Is polar as a result of the electrons spending more time near the electronegative oxygen atom.

                                                            ii.      Can form hydrogen bonds with water molecules, helping dissolve organic compounds such as sugars.

 

 

Term

 

Carbonyl

Definition

a.       Structure: (=CO) carbon atom double bonded to a oxygen atom.

b.      Compound: Ketones – if carbonyl group is within a carbon skeleton.

Aldehydes – if at the end of carbon skeleton.

c.       Functional Properties:

                                                              i.      A ketone and an aldehyde may be structural isomers with different properties, as is the case for acetone and propanal.

                                                            ii.      These two groups are also found in sugars, giving rise to 2 major groups of sugars, aldoses and ketoses.

Term
Carboxyl
Definition

a.       Structure: (-COOH) oxygen atom double bonded to a carbon atom that is also bonded to an –OH group.

b.      Compound: Carboxylic acids, or organic acids

c.       Functional Properties:

                                                              i.      Has acidic properties (is a source of hydrogen ions) because covalent bond between oxygen and hydrogen is so polar.

                                                            ii.      Found in cells in the ionized form with a charge of 1 – and called a carboxylate ion.

Term
Amino
Definition

a.       Structure: (-NH2) nitrogen atom bonded to two hydrogen atoms.

b.      Compound: Amines

c.       Functional Properties:

                                                              i.      Acts as a base; can pick up an H+ from the surrounding solution (water in living organisms).

                                                            ii.      Ionized, with a charge of 1+, under cellular conditions.

Term

 

Sulfhydryl

Definition

a.       Structure: (-SH or HS-) sulfur atom bonded to hydrogen atom.

b.      Compound: Thoils

c.       Functional Properties:

                                                              i.      Two sulfhydryl groups can react, forming a covalent bond. This “cross-linking” helps stabilize protein structure.

                                                            ii.      Cross-linking of cysteines in hair proteins maintains the curliness or straightness of hair.

Term
Phosphate
Definition

a.       Structure: (P) phosphorus atom is bonded to 4 oxygen atoms; 1 oxygen is bonded to the carbon skeleton; 2 oxygens carry negative charges.

b.      Compound: Organic phosphates

c.       Functional Properties:

                                                              i.      Contributes negative charge to the molecule of which it is a part.

                                                            ii.      Has the potential to react with water, releasing energy.

Term

 

Polymer

Definition

 

A long molecule consisting of many similar or identical building blocks linked by covalent bonds.

 

 

Term

 

Condensation Reaction > Dehydration Reaction

Definition

 

 

A reaction in which two molecules are covalently bonded to each other through loss of a water molecule

 

Term

 

Hydrolysis Reaction

Definition

 

 

Chemical process that splits molecules by the addition of water, functioning in disassembly of polymers and monomers.

 

Term

 

Carbohydrates

Definition

o   Sugars or polymers of sugars

o   Transport or store energy

o   Structure

o   Hydrophilic – water soluble, polar

Term

 

Monosaccharides

Definition

 

o   Glucose, fructose, diverse (many isomers)

 

 

Term

 

Disaccharides

Definition