Biol 2404 2.1

Front 1

What is matter composed of?

Back 1

Elements

Front 2

What is an element?

Back 2

Any substance that cannot be broken down into another substance, at least by any normal chemical reaction

Front 3

How many naturally occurring elements do we have?

Back 3

92 - others have been created or synthesized by scientists

Front 4

How many elements are considered essential for life and how many of them make up 96% of our body mass?

Back 4

25 elements, 4: carbon, nitrogen, oxygen, and hydrogen

Front 5

Smallest units of matter?

Back 5

Atoms

Front 6

What are atoms composed of?

Back 6

Subatomic particles: electrons, protons, and neutrons

Front 7

What are protons?

Back 7

subatomic particles found in the nucleus of the atom. Have a positive charge and an atomic mass of 1

Front 8

What are neutrons?

Back 8

Subatomic particles found in the nucleus of the atom. Have an atomic mass of 1, but neutrons don't have positive or negative charge so they are neutral

Front 9

What are electrons?

Back 9

Subatomic particles that are NOT found in the nucleus. Found way far away from the nucleus and orbiting/circling the nucleus. Electrons have a negative charge

Front 10

What is Atomic Mass?

Back 10

Equal to the number of protons plus the number of neutrons in the atom

Front 11

What is Atomic Number?

Back 11

The number of protons in an atom

Front 12

What determines the identity of an element?

Back 12

Atomic Number

Front 13

What are isotopes?

Back 13

Atoms of an element that have a different number of neutrons so they have different atomic masses but same atomic number

Front 14

What are unstable isotopes called?

Back 14

Radioactive isotopes. When they decay the energy they give off is radiation

Front 15

3 ways of representing atoms

Back 15

1.The shell model

2. The ball model

3. The electron density cloud model

Front 16

How do the electrons of an atom fill the shells?

Back 16

The innermost shell (1st shell), then the 2nd shell is filled, then 3rd etc

Front 17

How many electrons can each shell hold?

Back 17

1st electron shell holds 2, the 2nd shell holds eight

Front 18

What is valence shell?

Back 18

The outermost shell of an atom, holds valence electrons

Front 19

What happens if the valence shell is not full?

Back 19

It is considered unstable and will interact with the valence electrons of other atoms so that it can fill the outermost shell

Front 20

How is a molecule created?

Back 20

When 2 or more atoms bond together

Front 21

What is a compound?

Back 21

Molecules that contain atoms of more than one element in proportions that do not vary

Front 22

2 Primary Types of Chemical Bonds

Back 22

Ionic Bonds and Covalent Bonds

Front 23

What is an ion?

Back 23

An atom of molecule that has a net electric charge

Front 24

What is an Ion with a positive charge?

Back 24

Cation : if an atom loses electrons, it is left with a net positive charge (because it has more protons than electrons)

Front 25

What is an ion with a negative charge?

Back 25

Anion : if an atom gains electrons, it develops a net negative charge

Front 26

What's an ionic bond?

Back 26

Electrical attraction between cation and anion

Front 27

How are covalent bonds formed?

Back 27

When atoms share electrons in their valence shells

Front 28

What is a single covalent bond?

Back 28

If atoms share a single pair of electrons

Front 29

What is a double covalent bond?

Back 29

If atoms have to share 2 pairs of electrons in order to fill the valence shell

Front 30

Non-polar covalent bonds

Back 30

Are created when atoms share the electrons equally

Front 31

Polar covalent bonds

Back 31

Are created when there is unequal sharing of electrons

Front 32

When are polar covalent bonds created?

Back 32

When one of the atoms has a stronger pull on the electron, compared to the other atom

Front 33

Electronegative

Back 33

The atom with the stronger pull (electronegativity of an atom is the tendency to attract electrons)

Front 34

What do polar covalent bonds lead to the creation of?

Back 34

Polar Molecules

Front 35

What are polar molecules?

Back 35

A molecule that will have one region that has a slight negative charge and one region that has a slight positive charge (so it has two 'poles')

Front 36

Which is the most important polar molecule in our body?

Back 36

H20 (Oxygen has the stronger pull on the electron so it is an electronegative atom)

Front 37

What is a hydrogen bond?

Back 37

The attraction between a slight positive charge on the hydrogen atom of one polar molecule and a slight negative charge of an oxygen or nitrogen of another polar molecule

Front 38

What happens during chemical reactions?

Back 38

Chemical bonds are formed or broken

Front 39

What is the formula for chemical reaction?

Back 39

Reactants + Reaction = Products (resulting molecule that is produced)

Front 40

What does catabolism refer to?

Back 40

The decomposition reactions that occurs within a cell

Front 41

Decomposition Reaction

Back 41

When large, complex molecules are broken down in the body, a molecule of water is absorbed during the process

Front 42

Hydrolysis

Back 42

Water molecule that is necessary for the breakdown to occur

Front 43

What does anabolism refer to?

Back 43

The synthesis of new molecules in the body

Front 44

Synthesis Reaction

Back 44

when smaller molecules are used to create larger moleucles

Front 45

Dehydration synthesis

Back 45

a complex molecule is formed by the removal of water (opposite of hydrolysis)

Front 46

What is reversible reactions?

Back 46

Chemical reactions that can occur in both directions - synthesizing or decomposing

Front 47

What is activation energy?

Back 47

The amount of energy that is necessary to start a chemical reaction

Front 48

What do enzymes do?

Back 48

They speed up chemical reactions by lowering the activation energy. Act as catalysts for chemical reactions