bio unit 2 notes pp.pptx

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Biology Unit 2

The Chemistry of Life

Biology Unit 2

The Chemistry of Life

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2A – Basic Chemistry



_{A science that deals with the composition, structure,}

and properties of substances and with the

transformations that they may undergo.



_{A science that deals with the composition, structure,}

and properties of substances and with the

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2A – Basic Chemistry

A.Matter

1. Definition

a. Anything that occupies space and has mass

b. Three states of matter

1. Solid 2. Liquid 3. Gas

A. Matter

1. Definition

a.

Anything that occupies space and has mass

b.

Three states of matter

1. Solid

2. Liquid

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2A – Basic Chemistry

2. Composed of over 109 known elements

a. Pure substances that cannot be broken down further into

simpler substances by ordinary chemical reactions

b. Periodic table of elements

1. The arrangement of elements according to the structure of their atoms

2. Composed of over 109 known elements

a.

Pure substances that cannot be broken down further into

simpler substances by ordinary chemical reactions

b.

Periodic table of elements

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2A – Basic Chemistry

Atomic number   # of protons, # of electrons

Name 

Symbol 

Atomic Mass   # of protons + # of neutrons Electron Arrangement

by energy level   # of electrons

Atomic number   # of protons, # of electrons

Name 

Symbol 

Atomic Mass   # of protons + # of neutrons Electron Arrangement

by energy level   # of electrons

20 Calcium

CA

40.08

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2A – Basic Chemistry

c. Table of elements common to life c. Table of elements common to life

Symbol Element % in

Human Body O C H N Ca Oxygen Carbon Hydrogen Nitrogen Calcium 65 18

10 98 3

2 P

K Phosphorus Potassium

.5 – 1 each

S Cl Na Mg Sulfur Chlorine Sodium Magnesiu m

.1 - .5 each

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2A – Basic Chemistry

d. The atom

1. The smallest unit of an element that still exhibits the

characteristics of that element

2. Nucleus – the center of the atom

a. Protons – positively charged particles inside the nucleus b. Neutrons – neutral particles inside the nucleus

c. Electrons – negatively charged particles outside the nucleus

1. “Orbit” the nucleus at varying levels or distances – electron shells

d. The atom

1. The smallest unit of an element that still exhibits the

characteristics of that element

2. Nucleus – the center of the atom

a. Protons – positively charged particles inside the nucleus

b. Neutrons – neutral particles inside the nucleus

c. Electrons – negatively charged particles outside the nucleus

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2A – Basic Chemistry

3. The opposing charges of protons and electrons hold an atom together

4. Most atoms are unstable and will “bond” with another to become stable

a. An atom is stable when it’s outermost electron shell is full = 8 electrons b. But atoms can have the following electrons in their shells

1. Level 1: 2 electrons 2. Level 2: 8 electrons 3. Level 3: 18 electrons 4. Level 4: 32 electrons

3. The opposing charges of protons and electrons hold an atom together

4. Most atoms are unstable and will “bond” with another to become stable

a. An atom is stable when it’s outermost electron shell is full = 8 electrons

b. But atoms can have the following electrons in their shells

1. Level 1: 2 electrons

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2A – Basic Chemistry

c.

Atoms will react and share the electrons in their outermost shells

to “fill” them ~

goal is to be complete with 8 electrons in the

outermost shell!

1. Chlorine (Cl) – 2, 8, 7 2. Sodium (Na) – 2, 8, 1

a. Chlorine (Cl) easily takes the 1 electron from sodium (Na) to make it’s outermost shell full

b. Sodium now has a full outermost shell at 8 c. Na + Cl  NaCl or sodium chloride/salt

c.

Atoms will react and share the electrons in their outermost shells

to “fill” them ~

goal is to be complete with 8 electrons in the

outermost shell!

1. Chlorine (Cl) – 2, 8, 7

2. Sodium (Na) – 2, 8, 1

a. Chlorine (Cl) easily takes the 1 electron from sodium (Na) to make it’s outermost shell full

b. Sodium now has a full outermost shell at 8

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2A – Basic Chemistry

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2A – Basic Chemistry

d. When one atom takes an electron or loses an electron, it

becomes an ION

1. Ion = a “charged” atom

2. No longer the same (equal) number of protons and electrons

a. Sodium has lost an electron, now has more protons (+) than electrons (-) so it becomes a positive ion – cation

b. Chlorine gained an electron (-) making it a negative ion - anion

3. This is called an ionic bond

d. When one atom takes an electron or loses an electron, it

becomes an ION

1. Ion = a “charged” atom

2. No longer the same (equal) number of protons and electrons

a. Sodium has lost an electron, now has more protons (+) than electrons (-) so it becomes a positive ion – cation

b. Chlorine gained an electron (-) making it a negative ion - anion

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2A – Basic Chemistry

e. Covalent bond

1. When two atoms share electrons – a strong bond

e. Covalent bond

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2A – Basic Chemistry

B. Compounds

1. a substance made of two or more different elements

bonded together chemically

2. The smallest unit of a compound is a molecule – distinct

group of atoms bonded together

a. still that compound in a natural state

B. Compounds

1. a substance made of two or more different elements

bonded together chemically

2. The smallest unit of a compound is a molecule – distinct

group of atoms bonded together

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2A – Basic Chemistry

b. molecular formulas:

1. Express the number and type of atoms in a compound

2. C₆H₁₂O₆ ~ 6 carbons, 12 hydrogens, 6 oxygens (24 atoms total)

c. structural formulas:

3. Diagram showing where the atoms are actually located and the arrangement of chemical bonds

b. molecular formulas:

1. Express the number and type of atoms in a compound

2. C₆H₁₂O₆ ~ 6 carbons, 12 hydrogens, 6 oxygens (24 atoms total)

c. structural formulas:

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Glucose

:

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2A – Basic Chemistry

C. Chemical and Physical Changes

1. Chemical Change

a. When the atoms of a substance bond with different atoms or

compounds

b. The new substance has completely different characteristics than

its original parts

1. Sodium – a highly reactive metal, reacting violently in water

2. Chlorine – poisonous gas, when dissolved in water it kills bacteria 3. Together, sodium chloride is common table salt

C. Chemical and Physical Changes

1. Chemical Change

a.

When the atoms of a substance bond with different atoms or

compounds

b.

The new substance has completely different characteristics than

its original parts

1. Sodium – a highly reactive metal, reacting violently in water

2. Chlorine – poisonous gas, when dissolved in water it kills bacteria

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2A – Basic Chemistry

2. Physical Change

a. The process of altering the state of something, its appearance or

its combination with substances, but not involving change in

electron sharing or giving

3. Mixture

b. forms when 2 substances combine without chemical bonding

c. Can be seperated with heat or mechanical methods

2. Physical Change

a.

The process of altering the state of something, its appearance or

its combination with substances, but not involving change in

electron sharing or giving

3. Mixture

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2A – Basic Chemistry

D. Energy

1. the ability to do work or to cause a change

2. Two types of energy:

a. kinetic energy

1. Energy of motion (falling, heat, light, electricity, etc)

b. Potential energy

1. Stored energy (rock sitting on a cliff, log waiting to be burned, etc)

c. Kinetic energy <---> Potential energy

D. Energy

1. the ability to do work or to cause a change

2. Two types of energy:

a.

kinetic energy

1. Energy of motion (falling, heat, light, electricity, etc)

b.

Potential energy

1. Stored energy (rock sitting on a cliff, log waiting to be burned, etc)

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2A – Basic Chemistry

3. Laws of thermodynamics – man's statements of how energy

changes occur

a. 1st law of thermodynamics (law of conservation)

1. In any process, energy is neither created nor destroyed, it just changes form

b. 2nd law of thermodynamics

1. Whenever energy is used, some of it is rendered unusable

2. Not all energy that gets put into something is there at the end a. Some is released as heat or light (it doesn't disappear)

3. Entropy – increase in randomness and loss of usable energy

3. Laws of thermodynamics – man's statements of how energy

changes occur

a.

1st law of thermodynamics (law of conservation)

1. In any process, energy is neither created nor destroyed, it just changes form

b.

2nd law of thermodynamics

1. Whenever energy is used, some of it is rendered unusable

2. Not all energy that gets put into something is there at the end

a. Some is released as heat or light (it doesn't disappear)

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2A – Basic Chemistry

4. Chemical reactions and energy

a. The potential energy that fuels the processes of life is stored in

the bonds between their molecule's atoms

1. Occur during the reactions that form these molecules as well as those that break them down

4. Chemical reactions and energy

a.

The potential energy that fuels the processes of life is stored in

the bonds between their molecule's atoms

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2A – Basic Chemistry

b. 2 types of chemical reactions:

1. Endothermic

a. Reactions that require or absorb heat

b. Example: baking a cake

2. Exothermic

a. Reactions that give off heat

b. Example: burning a piece of wood

b. 2 types of chemical reactions:

1. Endothermic

a.

Reactions that require or absorb heat

b.

Example: baking a cake

2. Exothermic

a.

Reactions that give off heat

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2A – Basic Chemistry

c. Writing chemical reactions:

1. Reactants – what goes into the reaction

2. Products – what comes out of the reaction

A + B ---> C + D

Reactants Products

c. Writing chemical reactions:

1. Reactants – what goes into the reaction

2. Products – what comes out of the reaction

A + B ---> C + D

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2A – Basic Chemistry

5. Catalysts and enzymes

a. Activation energy – the energy needed to start a chemical

reaction

1. Thermal, electrical, light, nuclear

b. Catalysts – substances that affect the rate of a reaction

1. They reduce the amount of activation energy needed for a reaction 2. They are very specific for their reaction

3. If a catalyst is needed for a reaction it is indicated by the following: catalyst

A + B ---> C + D

5. Catalysts and enzymes

a.

Activation energy – the energy needed to start a chemical

reaction

1. Thermal, electrical, light, nuclear

b.

Catalysts – substances that affect the rate of a reaction

1. They reduce the amount of activation energy needed for a reaction

2. They are very specific for their reaction

3. If a catalyst is needed for a reaction it is indicated by the following: catalyst

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2A – Basic Chemistry

c. Enzymes – organic catalysts that speed up chemical reactions

d. Substrate – the molecule the enzyme binds to

e. Active Site – part of the enzyme that binds to the substrate

c. Enzymes – organic catalysts that speed up chemical reactions

d. Substrate – the molecule the enzyme binds to

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2A – Basic Chemistry

E. Solutions

1. Living things are mostly water – humans average 57-60%

water

a. Other substances of life are dissolved or suspended in water

2. Solution

a. Homogenous mixture of one or more substances within another

substance

1. Appears the same throughout

E. Solutions

1. Living things are mostly water – humans average 57-60%

water

a.

Other substances of life are dissolved or suspended in water

2. Solution

a.

Homogenous mixture of one or more substances within another

substance

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2A – Basic Chemistry

b. Solute vs. Solvent

1. Solute – the substance being dissolved (example: salt)

2. Solvent – the substance doing the dissolving (example: water)

c. The % of solutes to solvents can change

3. The concentration of a solution is the ratio of the solute in the solvent 4. Take a look at a bottle and you will see the amount of solute present

a. Example – 10% glucose = 10 grams of glucose / 100 grams water

b. Solute vs. Solvent

1. Solute – the substance being dissolved (example: salt)

2. Solvent – the substance doing the dissolving (example: water)

c. The % of solutes to solvents can change

3. The concentration of a solution is the ratio of the solute in the solvent

4. Take a look at a bottle and you will see the amount of solute present

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2A – Basic Chemistry

3. Diffusion

a. The movement of molecules from an area of higher

concentration to an area of lower concentration – down the

concentration gradient

b. When an equilibrium has been reached, the diffusion stops

4. Osmosis

c. The movement of water from an area of higher concentration ot

areas of lower concentration

3. Diffusion

a.

The movement of molecules from an area of higher

concentration to an area of lower concentration – down the

concentration gradient

b.

When an equilibrium has been reached, the diffusion stops

4. Osmosis

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2A – Basic Chemistry

F. The pH scale

1. Most substances, when dissolved in water are either acids or

bases

a. Acid – a compound that donates hydrogen ions (H+) when dissolved

in water

1. PH of less than 7

b. Base – a compound that releases hydroxide ions (OH-) ions when

dissolved in water

1. PH of greater than 7

F. The pH scale

1. Most substances, when dissolved in water are either acids or

bases

a.

Acid – a compound that donates hydrogen ions (H+) when dissolved

in water

1. PH of less than 7

b.

Base – a compound that releases hydroxide ions (OH-) ions when

dissolved in water

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2A – Basic Chemistry

2. pH is very important to the human body

a. Example – cancer thrives in an acidic environment and cannot

survive in pH of 8.4 +

b. Many human illnesses are attributed to an acidic environment

2. pH is very important to the human body

a.

Example – cancer thrives in an acidic environment and cannot

survive in pH of 8.4 +

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2B – Organic Chemistry

A. Organic Compounds

1. Based on the carbon atom and its bonding characteristics

a. Usually bonded with hydrogen and sometimes oxygen

b. Carbon has 4 electrons in its outer shell and shares them easily c. Carbon backbone

1. Chain or ring of carbons bonded to one another

C - C single bond (shares 1 electron) C = C double bond (shares 2 electrons) C = C triple bond ( shares 3 electrons)

A. Organic Compounds

1. Based on the carbon atom and its bonding characteristics

a. Usually bonded with hydrogen and sometimes oxygen

b. Carbon has 4 electrons in its outer shell and shares them easily

c. Carbon backbone

1. Chain or ring of carbons bonded to one another

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2B – Organic Chemistry

2. Functions of organic compounds

a. Structural – compounds that are used as building blocks

b. Enzymatic – compounds that are enzymes or help enzymes function c. Storage – compounds that store energy, other substances

3. Atoms bond to form molecules, molecules bond to form macromolecules

2. Functions of organic compounds

a. Structural – compounds that are used as building blocks

b. Enzymatic – compounds that are enzymes or help enzymes function

c. Storage – compounds that store energy, other substances

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2B – Organic Chemistry

B. All organisms are composed of 4 macromolecules

1. Carbohydrates 2. Lipids

3. Proteins

4. Nucleic Acids

B. All organisms are composed of 4 macromolecules

1. Carbohydrates

2. Lipids

3. Proteins

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2B – Organic Chemistry

C. Carbohydrates

1. An organic macromolecule made of carbon, hydrogen and oxygen 2. 1 C : 2 H : 1 O

3. A good energy source because bonds store a lot of energy 4. Types of carbohydrates:

C. Carbohydrates

1. An organic macromolecule made of carbon, hydrogen and oxygen

2. 1 C : 2 H : 1 O

3. A good energy source because bonds store a lot of energy

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2B – Organic Chemistry

a. Monosaccharides (sugars)

1. 5 carbon monosaccharide – ribose

2. 6 carbon monosaccharide – glucose, fructose

a. Monosaccharides (sugars)

1. 5 carbon monosaccharide – ribose

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2B – Organic Chemistry

b. Disaccharides

1. When 2 monosaccharides are joined together by enzymes

2. glucose + fructose = sucrose (table sugar)

b. Disaccharides

1. When 2 monosaccharides are joined together by enzymes

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2B – Organic Chemistry

c. Polysaccharides

1. A complex molecule of monosaccharides bonded by enzymes 2. Starch

a. Long, unbranched chain of glucose molecules

c. Polysaccharides

1. A complex molecule of monosaccharides bonded by enzymes

2. Starch

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2B – Organic Chemistry

3. Glycogen

a. Long, branched chain of glucose molecules

3. Glycogen

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2B – Organic Chemistry

4. Cellulose

a. Long chains of glucose molecules bonded in an alternating pattern b. Very strong bond, doesn’t break easily

c. Major component in cell wall of plants

d. Passes undigested through human body easily

4. Cellulose

a. Long chains of glucose molecules bonded in an alternating pattern

b. Very strong bond, doesn’t break easily

c. Major component in cell wall of plants

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2B – Organic Chemistry

D. Lipids

1. Organic macromolecules that are not soluble in water, but soluble in oil 2. 2 main classifications of lipids:

a. Oils, fats, waxes

1. Fatty acid molecules – most abundant type of lipid a. Energy storage molecules

b. Have more C – H bonds than carbohydrates

c. Contains a “fatty acid” unit – long chain of carbon and hydrogen bonded to a carboxylic group (COOH) at the end

d. Most fatty acids are bonded to a glycerol molecule as well - triglycerides

D. Lipids

1. Organic macromolecules that are not soluble in water, but soluble in oil

2. 2 main classifications of lipids:

a. Oils, fats, waxes

1. Fatty acid molecules – most abundant type of lipid

a. Energy storage molecules

b. Have more C – H bonds than carbohydrates

c. Contains a “fatty acid” unit – long chain of carbon and hydrogen bonded to a carboxylic group (COOH) at the end

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2B – Organic Chemistry

2. Saturated vs. Unsaturated

a. Saturated: most carbons are bonded to 2 hydrogen atoms 1. Carbons are “saturated” by hydrogens

2. Solids at room temperature

b. Unsaturated: some carbons linked with other carbons by a double bond 1. Kinks in the chain

2. Oils at room temperature

c. Saturated fats in your diet can cause heart disease

2. Saturated vs. Unsaturated

a. Saturated: most carbons are bonded to 2 hydrogen atoms

1. Carbons are “saturated” by hydrogens

2. Solids at room temperature

b. Unsaturated: some carbons linked with other carbons by a double bond

1. Kinks in the chain

2. Oils at room temperature

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2B – Organic Chemistry

b. Phospholipids

1. A phosphate head attached to a fatty acid tail

b. Phospholipids

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2B – Organic Chemistry

c. Steroids

1. Composed of 4 rings of carbon atoms fused together 2. Example - cholesterol

c. Steroids

1. Composed of 4 rings of carbon atoms fused together

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2B – Organic Chemistry

E. Proteins

1. Organic macromolecules made of long chains of amino acids

a. Made up of a carboxyl group (COOH) + amino group (NH2) attached to a carbon backbone

E. Proteins

1. Organic macromolecules made of long chains of amino acids

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2B – Organic Chemistry

2. Are made up of 20 amino acids arranged in different orders 3. Can bend, twist, curl, or fold into complex shapes

4. Act as enzymes and are needed in chemical reactions 5. Polypeptide

a. A chain of amino acids

2. Are made up of 20 amino acids arranged in different orders

3. Can bend, twist, curl, or fold into complex shapes

4. Act as enzymes and are needed in chemical reactions

5. Polypeptide

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2B – Organic Chemistry

F. Nucleic Acids

1. Hereditary materials

a. Contains all the information for how an organism will grow and develop

2. Made of nucleotides:

a. 5 carbon sugar b. Phosphate group c. Nitrogen base

3. 3 types:

a. DNA – deoxyribonucleic acid b. RNA – ribonucleic acid

F. Nucleic Acids

1. Hereditary materials

a. Contains all the information for how an organism will grow and develop 2. Made of nucleotides:

a. 5 carbon sugar

b. Phosphate group

c. Nitrogen base 3. 3 types:

a. DNA – deoxyribonucleic acid

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