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Macromolecules

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Organic Compounds • Compounds that contain CARBON

are called organic.

• 4 Elements found in organisms – Carbon -Oxygen

– Hydrogen -Nitrogen

• Macromolecules are large organic molecules.

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Carbon (C) • Carbon has 4 electrons in outer shell.

• Carbon can form covalent bonds with as many as 4 other atoms (elements).

• Usually with C, H, O or N. (CHON)

• Example: CH4(methane)

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Macromolecules

• Large organic molecules. • Also called POLYMERS. • Made up of smaller “building blocks” called MONOMERS.

• Examples: 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic acids (DNA and RNA)

Polygons

Polygamy Polyester

What is so special about Macromolecules?

• Most of the energy

used by an organism

comes from

GLUCOSE

– By breaking the

chemical bonds and

releasing the energy

via cellular respiration

• Other “macros”

provide vital

functions such as

proteins (enzymes)

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Carbohydrates

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Carbohydrates = Sugars

• Provides energy and support – Support: Cellulose for plants – Energy: breakdown of glucose (cellular respiration)

• Range from small molecules to large molecules.

CARBOHYDRATES

Each carbohydrate is made up of…

THINK: “CHO”

Types of Carbohydrates

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A. monosaccharide B. disaccharide C. polysaccharide

Glucose • Most common monomer or

monosaccharide

• 1 glucose molecule

– C6H

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6 or 1:2:1 ratio

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Carbohydrates- Simple

Monosaccharide: one sugar unit

Examples: glucose

deoxyribose

ribose

fructose

galactose

glucose

Examples of Monosaccharides

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• Glucose – sugar (beet, cane)

• Fructose – fruits

• Galactose – dairy

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Carbohydrates- Simple

Disaccharide: two sugar unit

Examples: – Sucrose (glucose+fructose)

– Lactose (glucose+galactose)

– Maltose (glucose+glucose)

glucose glucose

Examples of Disaccharides

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• Sucrose – table sugar

• Lactose – dairy

• Maltose - sweetener

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Carbohydrates - Complex Polysaccharide: many sugar units

Examples: starch (bread, potatoes)

glycogen (beef muscle)

cellulose (lettuce, corn)

glucose glucose

glucose glucose

glucose glucose

glucose glucose

cellulose

Examples of Polysaccharides

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• Starch – sugar (beet, cane)

• Cellulose – fruit and vegetables

• Chitin – exoskeleton

• Glycogen - meat

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Lipids

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Lipids • General term for organic molecules which are not soluble in water.

• Lipids are soluble in hydrophobic solvents.

• Remember: “stores the most energy” • Examples: 1. Fats 2. Phospholipids 3. Oils 4. Waxes 5. Steroid hormones 6. Triglycerides

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Lipids Six functions of lipids: 1. Long term energy storage 2. Protection against heat loss (insulation) 3. Protection against physical shock 4. Protection against water loss 5. Chemical messengers (hormones) 6. Major component of cell membranes (phospholipids)

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Lipids Triglycerides: -composed of 1 glycerol and 3 fatty acids.

H

H-C----O

H-C----O

H-C----O

H

glycerol

O

C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3

fatty acids (chains)

O

C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3

O

C-CH2-CH2-CH2-CH

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Fatty Acids There are two kinds of fatty acids- you may see

these on food labels:

1. Saturated fatty acids: no double bonds (bad)

2. Unsaturated fatty acids: double bonds (good)

O

C-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3 saturated

O

C-CH2-CH2-CH2-CH unsaturated

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Proteins

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Proteins (Polypeptides) • Made up of amino acids (20 different kinds)

bonded together by peptide bonds (polypeptides).

• Six functions of proteins: 1. Storage: albumin (egg white) 2. Transport: hemoglobin transport 02

3. Regulatory: hormones 4. Movement: muscles 5. Structural: membranes, hair, nails 6. Enzymes: cellular reactions

MORE ON PROTEINS…

The following slides give you a little more in depth info on things that are made of

proteins…

Muscles, ligaments, tendons, and bones

Without these particular structural proteins, we would look more like this….

Hair and Nails

Microscope View of Skin and Nails

This is skin This is a nail

Cell Membrane

The cell membrane surrounds everything in a cell so it

doesn’t leak out. It is kind of like the balloon in

a water balloon.

The cell membrane is made mostly of protein AND lipids or phospholipid bilayer.

Enzymes • Main function is to act as a catalyst to speed up

chemical reactions. – KEY: Enzymes only speed up the process….they DO

NOT change the process

• Names of enzymes generally end in –ase. – Example: lactase, amylase, protease, maltase, etc.

• Helps an organism maintain homeostasis.

• Enzymes are everywhere……all biological processes involve enzymes.

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How does an enzyme work?

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• The enzyme weakens the chemical bonds of the substrate (e.g. lactose) which decreases the amount of energy needed to active the chemical reaction for the breakdown

• The enzyme enables the

breakage of the chemical bond to happen more efficiently!

Why is this important?

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Helps organisms conserve energy….more efficient!

How does an enzyme work? continued • Enzymes only work on a specific substrate (or

substance)

• Substrate is the substance that is being “processed” (i.e. broken down) or changed

• Active site is where chemical reaction between the enzyme and substrate occurs – Point of contact

– “Lock and key” mechanism

– Right key (size & shape)

to fit lock

• Enzyme problems: – Lactose intolerance 33

Lock and Key

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The right shape

and size must fit to active reaction!

Induced Fit

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• With some enzymes, the lock and key analogy doesn’t fit

• Induced fit: • The substrate changes (or induces) the shape

of the active site to make the active site conform and fit the shape of the substrate.

• Occurs when the substrate attaches to the right enzyme

• During this process, the bonds in the substrate weaken and thus reducing activation energy

Induced Fit Model

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Factors Affecting Enzymes

The following alter the rate of reaction:

Environmental Conditions

Cofactors & coenzymes

Enzyme inhibitors

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Factors Affecting Enzymes • Environmental Conditions

– Temperature • Increased temperature can denature the enzyme

• Denature= the deactivation or breakdown of the enzyme – Enzymes can “unfold” due to denaturing which cause permanent

damage to the enzyme and decreased rate of reaction

• Optimal temperatures for enzymes are different for different enzymes and organisms…humans it is 37°C

– pH and acidity

– Ion Concentrations • Too salty; too many enzymes; too many substrates

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Factors Affecting Enzymes • Cofactors and coenzymes

– Enzymes that require another enzyme to carry out reaction

– Examples: vitamins, iron, and zinc

• Enzyme inhibitors – Chemicals that reduce or inhibit enzyme reactions

– Examples: drugs or other chemicals that act as substrates and plug up the enzyme

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Nucleic Acids

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Nucleic acids

• Two types: a. Deoxyribonucleic acid (DNA- double helix)

b. Ribonucleic acid (RNA-single strand)

• Nucleic acids are composed of long chains of nucleotides

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Nucleic acids • Nucleotides include: phosphate group pentose sugar (5-carbon) nitrogenous bases: adenine (A) thymine (T) DNA only uracil (U) RNA only cytosine (C) guanine (G)

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Nucleotide

O

O=P-O

O

Phosphate

Group

N Nitrogenous base

(A, G, C, or T)

CH2

O

C1 C4

C3 C2

5

Sugar

(deoxyribose)

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DNA - double helix

P

P

P

O

O

O

1

2 3

4

5

5

3

3

5

P

P

P O

O

O

1

2 3

4

5

5

3

5

3

G C

T A