BIO Chapter 2 Flashcards

Matter

Anything that takes up space and has mass.

Four States of Matter

Solid, liquid, plasma, and gas.

Elements Important to Life

CHOPSTN (Carbon, Hydrogen, Oxygen, Phosphorus, Sulfur, Nitrogen).

Protons

Positively charged particles found in the nucleus.

Electrons

Negatively charged particles.

Neutrons

Uncharged particles found in the nucleus.

Molecules Form

When two or more of the same elements bond together.

Compounds Form

When two or more different elements bond together.

Ionic Bonding

When electrons are transferred from one atom to another.

Covalent Bonding

The result when atoms share electrons.

Nonpolar Covalent Bond

A bond where the sharing of electrons between two atoms is fairly equal.

Electronegativity

The attraction of an atom for electrons in a covalent bond.

Polar Covalent Bond

A bond where the sharing of electrons between atoms is unequal, as seen in water between oxygen and hydrogen.

Hydrophilic Molecules

Molecules that attract water.

Hydrophobic Molecules

Molecules that do not attract water.

Soap

Also called Amphipathic, because it is both hydrophilic and hydrophobic.

Fats, Grease, and Oil

Classified as Hydrocarbons.

Water Ionization

It releases an equal number of hydrogen ions (H+) and hydroxide ions (OH-).

Polarity in Water Molecules

Causes hydrogen atoms in one water molecule to be attracted to the oxygen atom in other water molecules.

Hydrogen Bond

The attraction between partially negative oxygen and partially positive hydrogen.

Strength of Hydrogen Bonds

They are weak individually but strong collectively.

Broken Lines in Chemical Diagram

Indicate that the bond is unstable.

First Cells Evolution Location

In water.

Percentage of Organisms Composed of Water

70-90%.

Water as a Polar Molecule

Due to its unequal sharing of electrons.

Water Molecules Cling Together

Because of hydrogen bonds.

Water's Property Due to Hydrogen Bonds

High heat capacity.

Calorie in Terms of Water

The amount of heat energy needed to raise the temperature of 1g of water by 1°C.

Hydrogen Bonds Absorb Heat

They link water molecules, allowing water to absorb heat without a great change in temperature.

Water's Temperature Regulation Benefit

It allows organisms to maintain their normal internal temperature.

Water's High Heat of Vaporization

Converting 1g of the hottest water to gas requires an input of 540 calories of heat energy.

Water's Heat of Vaporization for Animals

Helps animals in a hot environment to release excess body heat and moderates temperatures along coasts.

Water as a Solvent

Facilitates chemical reactions both outside and within living systems due to its polarity.

Solution Content

Contains dissolved substances, which are called solutes.

Water Molecules Cohesive

They cling together due to hydrogen bonding.

Water Molecules Adhesive

Allow water to adhere to polar surfaces due to positive and negative poles.

Water as a Great Transport System

Because it is cohesive and adhesive.

Surface Tension

The stronger the force between molecules in a liquid, the greater the surface tension.

High Surface Tension Benefit for Insects

Allows them to walk on the surface of a pond or lake.

Frozen Water Density Compared to Liquid Water

Less dense.

Liquid Water Densest Temperature

4°C.

Water Expansion When It Freezes

A crystal lattice forms with hydrogen bonds farther apart.

Ice Floats on Liquid Water

Because it is less dense.

Acidic Solutions Characterization

High H+ concentrations.

Acids Definition

Substances that release hydrogen ions when dissociated in water.

pH Scale Indication

The acidity or alkalinity of a solution.

pH Scale Range

0-14.

pH Values Definitions

Below 7 is acidic, over 7 is alkaline, and 7 is neutral.

pH of Stomach Acid

1 (1x10^-1M).

pH Range of Human Blood

7.2-7.4.

Buffer Definition

A chemical or combination of chemicals that keep pH within normal limits.

Elements in Organic Molecules

Always include Carbon (C) and Hydrogen (H).

Organic Molecules with Only Hydrogen and Carbon

Hydrocarbons.

Model of DNA Structure Creator

James Watson and Francis Crick.

DNA Composition

A chain of Nucleotides.

Three Subunits of Each Nucleotide in DNA

Phosphoric acid (phosphate), a pentose sugar (deoxyribose), and a nitrogen-containing base.

DNA Structure Contributor

Rosalind Franklin.

Sugar in DNA

Deoxyribose.

Bases in DNA

Adenine, Guanine, Thymine, Cytosine.

Strands in DNA

Double stranded.

DNA Helix Structure

Yes.

Sugar in RNA

Ribose.

Bases in RNA

Adenine, Guanine, Uracil, Cytosine.

Strands in RNA

Single stranded.

RNA Helix Structure

No.

Possible Bases in DNA

Two purines (Adenine (A), Guanine (G)) and two pyrimidines (Thymine (T), Cytosine (C)).

DNA Replication

The process of copying one DNA double helix into identical double helices.

Key Enzyme in DNA Replication

DNA polymerases.

Semi-Conservative Replication

It uses each original strand as a template to produce a new complementary strand.

Daughter DNA Molecule Composition After Replication

One new chain of nucleotides and one from the parent DNA molecule.

Before DNA Replication Begins

The two strands of the parent molecule are hydrogen-bonded together.

Enzyme Unwinding DNA

DNA helicase.

New DNA Nucleotides Fit During Replication

By complementary base pairing along separated strands.

Enzyme Positioning New DNA Nucleotides

DNA polymerase.

Enzyme Sealing DNA Backbone After Replication

DNA ligase.

Result of DNA Replication

Two double helix molecules that are identical to each other and to the original DNA molecule.