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Unit 1: Level of organization

Chemistry (macromolecules)

Levels of organization: Unit 1

Small to large:

atoms → molecules →macromolecules

Then larger (microscopic stuff):

cells and their parts (organelles)

Then the types of tissues cells can build, and the

specializations and functions of each tissue

Levels of Organization

• Chemical/Molecular (simple)

• Cell

• Tissue

• Organ

• Organ system

• Organism (complex)

Figure 1.4 Levels of Organization

Organism Level

Organ System Level

Organ Level

Tissue Level

Cellular Level

Chemical or

Molecular Levels

.1nm

10nm

10m

1mm

1mm

120mm

1.7m

Size

All of the organ systems must

work together for a person to

remain alive and healthy.

Integumentary Skeletal

Muscular

Nervous

Endocrine

Cardiovascular Lymphoid

Respiratory

Digestive

Urinary

Reproductive

The cardiovascular system

includes the heart, the blood,

and blood vessels.

The heart is a

complex three-

dimensional organ.

Cardiac muscle tissue

constitutes the bulk of

the walls of the heart.

Cardiac muscle tissue

is formed from interlocking

heart muscle cells.

Heart muscle cells

contain within them

contractile

protein fibers.

Complex contractile

protein fibers are

organized from molecules.

Molecules are

formed from

interacting atoms.

Levels of Organization

• Chemical

– atoms combined to form molecules

– Over a dozen elements in the body

– Four of them make up 99% of the body

• Hydrogen, oxygen, carbon, and nitrogen

– Major classes of compounds

• Water

• Carbohydrates

• Proteins

• Lipids

• Nucleic acids

Figure 1.4 Levels of Organization (Part 3 of 3)

Chemical or

Molecular Levels

.1nm

10nm

10m Heart muscle cells

contain within them

contractile

protein fibers.

Complex contractile

protein fibers are

organized from molecules.

Molecules are

formed from

interacting atoms.

Levels of Organization

• Cell

– made of molecules

– The smallest living unit in the body

• Tissue

– consists of similar types of cells

– Many cells and some surrounding material

• Organ

– Combination of tissues that work closely

together

Figure 1.4 Levels of Organization (Part 2 of 3)

Organ Level

Tissue Level

Cellular Level 1mm

1mm

120mm The heart is a

complex three-

dimensional organ.

Cardiac muscle tissue

constitutes the bulk of

the walls of the heart.

Cardiac muscle tissue

is formed from interlocking

heart muscle cells.

Levels of Organization

• Organ System

– Combination of various organs make up a

specific system

• For example: the stomach, small intestine, large

intestine, liver, gallbladder, and pancreas make up

the digestive system

• Organism – made up of the organ

systems

– Humans are composed of 11 organ systems

Figure 1.4 Levels of Organization (Part 1 of 3)

Organism Level

Organ System Level

1.7m

Size

All of the organ systems must

work together for a person to

remain alive and healthy.

Integumentary Skeletal

Muscular

Nervous Endocrine

Cardiovascular Lymphoid

Respiratory Digestive

Urinary

Reproductive

The cardiovascular system

includes the heart, the blood,

and blood vessels.

Molecules: (more than one atom)

• Molecules containing carbon + other atoms = organic

• Larger molecules (macromolecules) are built of linked molecules

• Categories: – Carbohydrates (built from simple sugars)

– Lipids (built from fatty acids)

– Protein (built from amino acids)

– Nucleic acids (built from nucleotides)

Molecules and macromolecules

• We eat mostly

macromolecules, and

digest them to

molecules

• We use molecules to

build components of

our tissues

• Each molecule and

macromolecule has

uses and chemical

properties

Organic Molecules

• Always contain:

– Carbon (C) and Hydrogen (H)

– A carbon atom may share electrons with another carbon atom or other atoms.

H C C C C C C C C H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

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Organic Molecules

• Macromolecules contain many molecules

joined together

– Monomers: Simple organic molecules that

exist individually

– Polymers: Large organic molecules form by

combining monomers

Organic Molecules

Polymer Monomer

carbohydrate (e.g., starch) monosaccharide protein amino acid nucleic acid nucleotide

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A meal containing carbohydrates, lipids, and proteins.

Organic Molecules

• Cells have common mechanisms

– Dehydration Reaction: an -OH and -H are

removed as a water molecule

– Hydrolysis Reaction: the components of

water are added

monomer monomer

monomer monomer

monomer monomer

OH H

OH H

b.

a.

monomer monomer

dehydration

reaction

hydrolysis

reaction

H2O

H2O

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Carbohydrates • Function for quick fuel & short-term energy storage H-C-OH

• Simple Carbohydrates

– Monosaccharides are sugars with 3 - 7 carbon atoms

– Pentose refers to a 5-carbon sugar

– Hexose refers to a 6-carbon sugar

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OH

OH

H

H

H

H

HO OH

H O

C

C

C

C C

4

5 6

3 2

1

OH

OH

H

H

H

HO OH

H O O

CH2OH CH2OH

C6H12O6

Carbohydrates

• Disaccharides contain two monosaccharides.

– Examples – maltose, sucrose, lactose

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OH HO

H H

O + +

O O O O

+ +

CH2OH

glucose C6H12O6 glucose C6H12O6

monosaccharide monosaccharide

CH2OH

dehydration reaction

hydrolysis reaction

CH2OH CH2OH

maltose C12H22O11

disaccharide

H2O

water

water

Carbohydrates

• Polysaccharides are long polymers that contain

many glucose subunits.

– Starch is the storage form of glucose in plants.

– Glycogen is the storage form of glucose in animals.

– Cellulose can be found in the cell walls of plants.

O

O O

H H H

H

OH H

OH

O

O

H H H

H

OH

OH

O

O

H H H

H

OH

OH

H H

O

O

H H H

H

OH

OH

H

starch

granule

cell wall

potato cells

nonbranched

branched

CH2OH CH2OH CH2OH CH2OH

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© Jeremy Burgess/SPL/Photo Researchers, Inc.

O

O O

H H

H

H

OH H

OH

O

O

H H

H

H

OH

OH

O

O

H H

H

H

OH

OH

H H

O

O

H H

H

H

OH

OH

H

glycogen

granule

liver cells

CH2OH CH2OH CH2OH CH2OH

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© Don W. Fawcett/Photo Researchers, Inc.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

O

OH

OH H

H

H

H

H

H

OH OH

H

H

H

H H H

OH

O

H H H

OH

O

O H

O

O

H

OH H

H OH

O

O O

O

OH

OH H

H

H

H

H

H

OH OH

H

H

H

H H H

OH

O

H H H

OH

O

O H

O

O

H

OH H

H OH

O

O O

O

OH

OH H H

H

H

H

H

OH OH

H

H

H

H H H

OH

O

H H H

OH

O

O H

O

O

H

OH H

H OH

O

O O

glucose

molecules

microfibrils

cellulose fibers

CH2OH CH2OH

CH2OH

CH2OH

CH2OH

CH2OH

CH2OH

CH2OH

CH2OH

CH2OH

CH2OH

CH2OH

cellulose

fiber

plant

cell wall

© Science Source/J.D. Litvay/Visuals Unlimited

Lipids

• Lipids function as energy storage molecules

• diverse in structure and function.

• One common characteristic – they do not dissolve in water (hydrophobic)

• Types

– Fats and oils

– Phospholipds

– Steroids

Lipids

• Fats

– Usually of animal origin

– Solid at room temperature

• Oils

– Usually of plant origin

– Liquid at room temperature

• Triglycerides

– One glycerol and 3 fatty acid molecules

• A fatty acid is a hydrocarbon chain that ends

with the acidic group —COOH

• Saturated fatty acids have no double covalent

bonds between carbon atoms.

• Unsaturated fatty acids have 1 or more double

bonds between carbon atoms. *

• Which one is better to eat?

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+

C OH H

H

C OH H

C

C

OH H

H

H

H

C O H

H

C O H

C O H

H

C

H

C

H

C

H

H

C O

C

H

H

H C

H O

H

C

H

C

H

C

H

H

C

C

C

H

H

H

O

C

H

H H H

C

H

C

H

C

H

H

C O

HO C

H

H

C

H

H

H C

H

H H H

C

H

C

H

C

H

H

C

O

C

H

H

C

H

H

H

C

H

H H H

C

H

C

H

C

H

H

C O

H C

H

H H H

C

H

C

H

C

H

H

H

HO

HO

+ 3 H2O

glycerol 3 fatty acids fat molecule

dehydration reaction

hydrolysis reaction

3 water

molecules

• Emulsification

– Fat droplets disperses in water.

– Emulsifiers contain molecules with a polar

and nonpolar end.

– Ex. Bile salts secreted by the liver

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polar end

nonpolar end

+

emulsifier emulsification fat

Lipids

• Phospholipids – Comprised of 2 fatty acids

+ a phosphate group

– Primary components of cellular membranes

– They spontaneously form a bilayer in which the hydrophilic heads face outward toward watery solutions and the tails form the hydrophobic interior.

– Purpose of bilayer?

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1CH

2 – O

– O

R –

O – P

– O

– 3C

H2

2CH

– O

O

O O C C

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH

CH

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH

CH

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH3

CH3

inside cell

outside cell

Fa

tty a

cid

s

a. Plasma membrane of a cell

Nonpolar Tails

Polar Head

glycerol

phosphate

b. Phospholipid structure

Lipids • Steroids

– All have a backbone of four fused carbon

rings.

• Examples: Cholesterol, Testosterone, Estrogen Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

HO

CH3

OH

O

CH3

CH3

OH

a. Testosterone b. Estrogen

Proteins • Proteins have various functions in the body

• Some are enzymes that speed chemical reactions

• polymers composed of amino acid monomers.

• Amino acids

– Central carbon bonded to a hydrogen atom

– Amino group (-NH2)

– Acidic group (-COOH)

– R group varies

H N C C

amino acid OH

H H

R

O N C C

amino acid

acidic group amino group

O

H R

H

OH

H

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

H

CH3

C C

O

O–

H

CH

CH3

C C

O

O–

H

CH2

SH

C C

O

O–

H

CH2

C C

O

O–

H3N+

H3N+

H3N+

H3C

H3N+

Proteins

• Peptides

– A polypeptide is a single chain of amino acids.

– A peptide bond joins two amino acids.

dehydration reaction H2O

water

H

H

R

H N C C N C C

H

H

R O

peptide bond

dipeptide

H N C C

amino acid

OH

H H

R

O

N C C

amino acid

acidic group amino group

O

H R

H

OH

O

OH

H hydrolysis reaction

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Proteins

• Levels of Protein Organization

– The structure of a protein has at least 3 levels

of organization.

• Primary, Secondary & Tertiary

• Some can have four.

– The final shape of a protein is very important

to its function.

• Denatured – A protein loses structure and function

due to heat or pH.

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(alpha) helix

COO– amino acid peptide bond

hydrogen bond

C N CH

R

C

CH

R

C N

C

CH

R

C

N

C

CH

R

N

C

CH

R

N

CH

R

N

C

N

CH

R

CH

hydrogen bond

(beta) pleated sheet

Linear

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(alpha) helix

disulfide bond

(beta) pleated sheet

Globular

More than 1 polypeptide chain

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(alpha) helix

COO– amino acid peptide bond

disulfide bond

hydrogen bond

C N

CH

R

C

CH

R

C N

C

CH

R

C

N

C

CH

R

N

C

CH

R

N

CH

R

N

C

N

CH

R

CH

hydrogen bond

(beta) pleated sheet

Nucleic Acids

• DNA (deoxyribonucleic acid)

– DNA stores genetic information in the cell and

in the organism.

• RNA (ribonucleic acid)

• Both are polymers of nucleotides

– Components of a nucleotide

• Phosphate

• Pentose sugar (ribose or deoxyribose)

• Nitrogen-containing base (1 of 5)

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O

4'

5'

3' 2'

1'

–O P O

O

O–

phosphate

nitrogen-

containing

base

pentose sugar

Nucleotide structure

C

S

C

• DNA is a double helix

• 2 strands held together by

hydrogen bonding

• Complementary base pairing

– Adenine (A) always pairs with

thymine (T)

– Cytosine (C) always pairs with

guanine (G)

• RNA is single stranded

– Several types involved in carrying

information in DNA to make

proteins

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A

A

T T G

G

C S

S

S

P

P

P

P

S

P

S

P

S

S

P

S

P

P

C

A

A

A

T

T

T

G

G C

C

S

S

P

a. b. c.

one nucleotide

a: © Radius Images/Alamy RF

Fig. 2B

1 / 2 1 / 2

MILK FRUITS GRAINS

Eat 6 oz.

every day

Eat 2 cups

every day

Eat 2 cups

every day

Consume 3

cups every

day; ages

2–8, 2 cups

Eat 5 oz.

every day

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VEGE TABLES MEAT & BEANS

YOU ARE WHAT YOU EAT!!!