Biochemistry PowerPoint

Chemistry of Life

IB Topic 3

#1. Elements, Atoms and Molecules

A. Elements are made of atoms

B. Elements cannot be broken down into simpler substances (this is not referring to subatomic particles)

C. Atoms=uncharged particles

D. Molecules=compounds made of two or more elements

Ex: H2O

#2. Covalent Bonds and Ionic Bonds

A. Covalent bonds-occur when molecules share electrons

-Example:H2O

OxygenHydrogen

+

WATER is covalently bondedhydrogen and oxygen.

B. Ionic bonds-occur when electrons are transferred between atoms

-results in one positive ion (cation) and one negative ion (anion)

-ionic bonds do not form molecules

-the exist in a crystalline lattice

-ions are more stabilized because their outer energy level becomes full

**ion=atom with a charge that has gained or lost electrons

#2. Covalent Bonds and Ionic Bonds

B. Ionic Bonds (continued)

#2. Covalent Bonds and Ionic Bonds

+Na Cl

Na+

+

Cl-

#3. Common Elements in Organisms

A. H, C, O = most common

B. Hydrogen forms one covalent bond

C. Oxygen forms two covalent bonds

D. Carbon forms four covalent bonds-can also form long chains with other carbon

atoms

#4. Other Common Elements

A. Nitrogen-part of amine groups in amino acids and other proteins

B. Calcium-needed to make the mineral that strengthens bones and teeth

C. Phosphorous-part of the phosphate groups in ATP and DNA molecules

D. Iron-needed to make hemoglobin and thus to carry oxygen in the blood

E. Sodium-used in neurons for the transmission of nerve impulses and maintaining electrical potential across membranes

F. Potassium-same general functions as sodium

#4. Other Common Elements

Homework

Outline the properties of water and how they are useful to living organisms as coolants, for metabolic reactions and transport.

Thermal properties

Cohesive properties

Solvent properties

#5. Water: General InfoA. Water is polar

B. Polarity is caused by unequal sharing of electrons of electrons

C. The oxygen is attracting more electrons than the hydrogen atoms

D. Oxygen becomes slightly negative

E. Hydrogen becomes slightly positive

F. The polarity of water causes it to form hydrogen bonds with other water molecules

G. Hydrogen bonds are formed by the attraction polar ends of water molecules

(negative end attracts positive end)

H. Hydrogen bonds are not chemical bonds

I. They are attractions of forces (electrons are not transferred or shared)

#5. Water: General Info (cont.)

#5. Water: General Info (cont.)

#6. Thermal Properties of Water

A. Heat capacity or specific heat-amount of energy required to raise the temperature by 1°C.

1. Water has a large heat capacity.

2. It can release or absorb a lot of heat without changing its temp.

3. Organisms with large amounts of water have more stable temps.

B. Heat of vaporization-amount of energy needed to evaporate 1.0g of water (540cal/g)

1. This is useful for humans when we sweat

2. The water that we perspire evaporates

3. The water on our skin absorbs 540 cal/g of heat from our bodies, then it evaporates

4. This is what cools us off

#6. Thermal Properties of Water (cont.)

C. Heat of fusion-amount of energy required to change 1.0 g of a solid to a liquid

#6. Thermal Properties of Water (cont.)

Homework: Due Wednesday

1. How do thermal properties of water keep temperatures in coastal regions more mild than inland areas?

D. Boiling point-100°C

1. The b.p. of water is high compared to many other fluids

2. For water to boil all hydrogen bonds must be broken

**Water can evaporate at temperatures below the boiling point. Hydrogen bonds are still broken.

#6. Thermal Properties of Water (cont.)

E. Freezing Point – 0°C

1. As water becomes solid it loses density, causing it to float

2. Water freezes at the surface first

3. The surface ice insulates the water underneath, keeping it from freezing

4. This allows aquatic organisms to survive the winter

#6. Thermal Properties of Water (cont.)

#7. Cohesive properties of water

A. Cohesion-water is attracted to water

1. It is caused by hydrogen bonds

2. It is responsible for surface tension

B. Adhesion-water’s attraction to other substances

A sphere exhibiting surface tension caused by cohesion

#7. Cohesive properties of water

C. Cohesive properties of water are especially important for plants

1. Capillary action-describes how water is able to move up the xylem2. Cohesion keeps the water molecules intact3. Adhesion attaches water to the xylem walls4. Capillary actions in plants is directly related

to transpiration

A. Water’s polarity allows it to dissolve most solutes (Water is the universal solvent.)

B. The positive side of a water molecule will attract the negative side of another molecule (and vice versa)

C. Example: Sodium chloride dissolves easily in water because it is charged

-Butters/oils/waxes will not dissolve in water because they are non-polar

#8. Solvent Properties of Water

#9. Water as a transport medium

A. Blood’s plasma is about 90% water

B. Many minerals and ions are dissolved in our blood, thus making water necessary for nutrient transport

C. Water is also necessary for nutrient transport in plants

#10. Water and metabolic processes

A. All metabolic processes require water1. Digestion

2. Assimilation

3. Cellular respiration

4. Metabolism

#11. Organic Compounds

A. Organic compound-any molecule containing carbon

-found in living systems

-carbon pairs most frequently with O, H and N

-carbon often uses covalent bonds to pair with other atoms

A. Continued-Example-Methane-CH4

#11. Carbohydrates, Lipids and Proteins (continued)

= H C H

H

H

H C H

H

H

=

Covalent Bonds

#12. Amino Acids

A. Amino acids=monomers of proteins

-organic molecules containing carboxyl groups and amino groups

B. Carboxyl group

COOH or COO-

C. Amino group

NH2 or NH3+

D. General amino acid

E. R group-rest of the amino acid

-can be many things

#12. Amino Acids

F. Amino acid example

Phenylalanine-makes up 50% of aspartame

#12. Amino Acids

or

Non-ionizedIonized

#13. Glucose

A. Chemical formula=C6H12O6

B. The most common monosaccharide

C. Hydroxyl groups are attached to every carbon, except one

D. A carbonyl group is attached to the other carbon (in the chain structure)

E. Can be found in a ring or a chain

F. Hydroxyl group -OH

G. Carbonyl group -C O

#13. Glucose

**R groups represent the rest of the molecule

Glucose structures

#13. Glucose

#13. GlucoseH. Comparison of

glucose structures -Notice the numbers on the carbon atoms

-Carbon 1 bond with the oxygen on carbon 5 to form the ring structure

-The new bond eliminates the double bond in the carbonyl group and the oxygen becomes part of the ring

-The ring structure is more stable because there are no dbl. bonds

#14. Ribose

A. Chemical formula=C5H10O5

B. Has hydroxyl groups and a carbonyl group

C. The structure and behavior is similar to glucose

D. There are hydrocarbon chains and rings

E. The rings are more stable because the double bonds in the carbonyl group are eliminated

F. Comparison of ribose structures

-carbon 1 bonds with carbon oxygen on carbon 4

-the double bond is eliminated

-oxygen becomes part of the ring

#14. Ribose

#15. Fatty acids

A. Fatty acids=carbon chains-usually 16-18 carbons in length

-have a carboxyl head and a hydrocarbon tail

B. Carboxyl= R-COOH

C. Hydrocarbon tail=carbon chain

CH3-(CH2)n-

D. General structure

#15. Fatty acids

CH3-(CH2)n-COOH

Carboxyl headHydrocarbon tail

**n=number of carbons between -CH3 and -COOH

#16. Glycerol

A. Glycerol=a chain of 3 carbons, with each having a hydroxyl group attached

B. Glycerol and fatty acids are the building blocks of fats

H C

OH

H

OH OH

C C

H H

H

Classwork/Homework

1. List three examples of each of the following:

-monosaccharides, disaccharides and polysaccharides.2. Draw one of each type of structure (the ones from your notes-glucose, ribose, amino acid, fatty acid, glycerol).3. Outline condensation and hydrolysis reactions. To do this, use chemical reactions and annotations.

Classwork/Homework1. Outline how polysaccharides are

converted into monosaccharides. [2]2. Describe the significance of water to

living organisms. [6]3. Draw a condensation reaction for two

amino acids. Label the peptide bond. [4]4. Draw a glucose molecule. [1]5. Draw hydrolysis reactions for the

following molecules. [2]

Triglyceride + 3H20

Dipeptide + 2H20

• For #’s 17, 18 and 19. See your handwritten notes that came from the ‘old school’ overhead projector!!

#20. Miscellaneous • The four main types of organic compounds

are carbohydrates, lipids, proteins and nucleic acids.

• Carbohydrates are our primary energy source ready for use

• Lipids are our primary source for energy storage

• Proteins are made of amino acids and have many uses

• Nucleic acids are our source of genetic material (RNA and DNA)

#21. Examples of CarbohydratesA. Monosaccharides

-glucose

-galactose

-fructose

-ribose

B. Disaccharides

-maltose -lactose

-sucrose

#21. Examples of Carbohydrates

C. Polysaccharides

-starch

-glycogen

-cellulose

#21. Examples of Carbohydrates

#22. Uses of Carbohydrates

A. Uses of carbohydrates in plants

1. Fructose-a sugar used for energy storage in plants

2. Sucrose-used for plant growth

3. Cellulose-provides support (the primary component of the cell wall)

B. Uses of carbohydrates in animals1. Glucose-primary source of energy in cellular respiration

-Used to produce ATP2. Lactose-another source of energy3. Glycogen-short term energy storage (the stored form of glucose)

-When the blood sugar is low glycogen is released

#22. Uses of Carbohydrates

#23. Functions of LipidsA. Energy storage

-fat in humans-oils in plants

B. Thermal insulation-in mammals and birds there is a fat layer used for reduction of heat loss

C. Buoyancy-lipids are less dense than water, allowing them to float

D. Steroid hormones-Used in hormones like adrenaline and testosterone

#24. Comparison of energy storage between carbohydrates and lipids

A. Lipids

-contain 2x as much energy as carbohydrates

-most ‘economic’ method of energy storage (take up less space per unit of energy)

-to store the same amount of energy in carbohydrates, twice as much space would be required

(carbs have 4cal/g and lipids have 9cal/g)

B. Carbohydrates

-more easily digested than lipids

-energy released more easily

-plants use these as energy storage

*they don’t need to move so they use the easiest method of energy storage (rather than most efficient)

#24. Comparison of energy storage between carbohydrates and lipids

Homework add on

6. In the red textbook go to p. 81

-Complete: Self Quiz #’s 1, 2 and 4.