Bio Honors Chapter 6

Atom

The building block of mater containing neutrons, protons, and electrons

Element

A pure substance made from only one type of atom and cannot be broken down

Compound

A pure substance formed when two or more different elements combine

Ion

An atom or molecule with a + or - charge because it lost or gained electrons

Isotopes

Two or more atoms of the same element, having a different number of neutrons

Molecule

A group of two or more atoms bonded together to make the smallest form of a pure substance, held together by covalent bonds

How many atoms are in the following molecule? H20

3

How many atoms are in the following molecule? CH3OH

6

How many atoms are in the following molecule? CH3COCH3

10

What are the four most abundant elements found in living things?

Oxygen, hydrogen, carbon, and nitrogen

what is a covalent bond?

A covalent bond is when an electron is shared between two nonmetals

What is an Ionic bond?

An ionic bond is when an electron is fully transferred from a metal to nonmetal

Define an endothermic reaction

An endothermic reaction traps heat and feels cold to the touch

Define exothermic reaction

An exothermic reaction releases heat and feels hot to the touch

What does number 1 represent

Active site

What does number 2 represent

Substrate

What does number 3 represent

Enzyme

Define activation energy

The smallest amount of energy needed to start a chemical reaction

Define enzyme

a protein that speeds up a chemical reaction to see faster results

define substrate

a molecule that an enzyme acts upon in a chemical reaction

define catalyst

a substance that speeds up a reaction without being exchanged itself

Define denaturing

Denaturing is when a protein looses its shape and cant function properly

Identify an environmental factor and explain how it can affect enzyme function

Temperature affects an enzymes function because it directly influences the energy and stability of the enzyme.

Identify an environmental factor and explain how it can affect enzyme function

The pH of the surrounding fluid affects the charges of the acid in the enzyme

Where is neutral on the pH scale?

7

Where are acids on the pH scale?

below 7

Where are bases on the pH scale?

above 7

define acid

An acid is a substance that releases hydrogen ions when dissolved in water and has a pH below 7

Define base

a substance that releases hydroxide ions and pH is above 7

draw a water molecule

Define polarity

A property of a molecule when the charges are unevenly distributed as + and -

define adhesion

the attraction between different types of molecules causing them to cling to each other

define cohesion

the attraction of molecules of the same kin causing them to cling

define capillary action

the ability for a liquid to flow upward through narrow spaces against gravity

define surface tension

a property of a liquids surface to resist external force

How does a hydrogen bond connect?

between two hydrogens (+)

How does a covalent bond connect?

between an oxygen and a hydrogen (+, -)

Define universal solvent

A substance that can dissolve a wide variety or elements, more than most others

Define solution

A homogeneous mixture composed of two or more substances

Define solute

The substance that is dissolved in the solvent

Define suspension

A heterogeneous mixture with large enough particles that they could settle over time

Define heterogeneous

A mixture where you can see the distinct substances

Define homogeneous

A mixture where the substances look the same

On the periodic table, each element has a unique _______ and ________

name and symbol

The periodic table in organized into horizontal rows called ______

Periods

The periodic table is organized into vertical columns called _____

groups

Water is a compound composed of ______ and _______

Hydrogen and Oxygen

what principle explains why there must be the same number of atoms of each element on each side of the equation

law for conservation of mass

define half life

The amount of time it takes for half of a radioactive isotope to decay

what number indicates the number of atoms of a substance

the subscript

what particles make up an atom? what are their charges?

proton (positive) neutron (neutral) electron (negative)

if oxygen has 8 protons, calculate the number of neutrons in the oxygen-16 atom. how do you find it?

You subtract 16-8 to get 8

for something to be a compound it cant vary, true or false

true

what is a buffer? why is it important?

A buffer is a small solution that resists changes in pH. this is important because can resist the big changes in pH during an experiment