Chapter 2 - Chemistry Comes Alive

Inorganic Compounds

• Do not contain carbon

• Ex: Water, Salts, Many acids and bases

• CO₂ and CO are exceptions to the rule

Organic Compounds

• Contains carbon

• Ex: Carbohydrates, Lipids, Proteins, Nucleic acids

properties of water

• High heat capacity (Absorb and release heat)

• High heat of vaporization (Water evaporation releases heat like sweating)

• Polar molecule > universal solvent (Transport medium & Lubricant)

• Reactivity (Important reactant in chemical reactions)

• Cushion (protection)

*Most abundant inorganic compound (Accounts for 60%–80% of the volume of living cells)

Hydrophilic substances

• Polar molecules

• Dissolve in water

• Ex: Polar molecules, Ions, Small proteins

Hydrophobic substances

• Nonpolar molecules

• Don’t dissolve in water

• Have to be transported via carrier proteins

• Ex: Nonpolar molecules & Metals

Amphipathic molecules

• Partially polar and nonpolar

• > partially dissolves

• Ex: Phospholipids & Glycolipids

monomer

• Single building block

• Form polymers via dehydration synthesis reactions

polymer

• Chain of repeating monomers

• Can be broken down into monomers via hydrolysis reactions

dehydration synthesis

monomers are joined by removal of OH from one monomer & removal of H from the other at the site of bond formation > anabolic

hydrolysis

monomers are released by the addition of a water molecule, adding OH to one monomer and H to the other

biological macromolecules always contain ?. may contain

always: C, H, O

may: N, P, S

elements of carbohydrates

Rings of carbons, where the number of C is equal to the number of O. (CH₂O)_n

Molecular formula of carbohydrates

(CH2O)_n

function of carbohydrates

Fuel

Cell membrane structure (limited)

are carbohydrates hydrophilic or hydrophobic?

hydrophilic

types of carbohydrates

Monosaccharides

Disaccharides

Polysaccharides

monomer of carbohydrates

monosaccharides (simple sugar)

examples of carbohydrates

Glucose

Fructose

Galactose

Ribose

Deoxyribose

two monosaccharides = ?. formed through ?

disaccharides; dehydration synthesis

1.     Most prominent carbohydrate

2.     Main source of energy for most cells

3.     Can be stored in the liver and skeletal muscle as glycogen.

glucose

Which monosaccharides combine to form sucrose

Glucose + Fructose

Which monosaccharides combine to form lactose

Glucose + Galactose

Which monosaccharides combine to form maltose

Glucose + Glucose

polysaccharides

• largest carbohydrate (made of many monosaccharide molecules)

• >Combined via dehydration synthesis reactions.

• low solubility (due to their size and branching)

• most prominent example in humans: glycogen

• other ex: Starch and cellulose (plants)

  

Glycogen can be broken down into ? when blood glucose is low.

• This is an example of ? feedback.

• Stored in the ? & ?

glucose; negative feedback; liver and skeletal muscles.

Glycogenesis

Storage of excess glucose in liver and skeletal muscle as glycogen

Glycogenolysis

Liver hydrolyzes glycogen into glucose when needed

Gluconeogenesis

Liver can make glucose from non-carbohydrate sources

does Glycogenesis increase or decrease blood glucose?

Decreases

does Glycogenolysis increase or decrease blood glucose?

Increases

does Gluconeogenesis increase or decrease blood glucose?

Increases

structure of lipids

C, H, O

function of lipids

Insulation

Fuel

Cell structure

are lipid molecules hydrophilic or hydrophobic?

hydrophobic

types of lipids

Fatty acids

Triglycerides

Phospholipids

Steroids

monomer of lipids

fatty acids

structure of fatty acids

• type of lipid

Carboxyl (COOH)

Hydrocarbon chain

classes of fatty acids

Saturated fatty acids

Monounsaturated fatty acids

Polyunsaturated fatty acids

Saturated fatty acids

• No double bonds

• solid @ room temp

Monounsaturated fatty acids

• 1 double bond

• liquid @ room temp

Polyunsaturated fatty acids

• 2 or more double bonds

• liquid @ room temp

  

triglycerides structure

• type of lipid

• structure: 3 fatty acids + glycerol

• Solids > fats

• Liquid > oils

  

triglycerides function

Energy storage and fuel (Lipogenesis and lipolysis)

Insulation

Protection

lipogensis

3 fatty acids + glycerol → triglyceride + H₂O

• Dehydration synthesis reaction

lipolysis

triglyceride + H₂O → 3fatty acids + glycerol

• Hydrolysis reaction

phospholipids structure

• type of lipid

• modified triglyceride

• Head (Polar)

>Phosphate-containing group

>Glycerol

• Tail (Nonpolar)

>2 Fatty acids

• amphipathic

phospohlipids function

Cell membrane structure

steroids structure

• type of lipid

4 fused carbon rings

Composed of fatty acids

functions of steroids

Cell membrane structure

Hormone synthesis

Bile synthesis

Vitamin D

cholesterol

a.     Component of cell membranes

b.    Used to make bile salts (digestion), hormones (testosterone and estrogen), and vitamin D

proteins structure

Always: C, H, O, N

Sometimes: S and P

monomer of amino acids

Amino acids

Joined by peptide bonds

functions of proteins

Cell structure

Enzymes

Transport

Movement

Communication

Defense

function of structural support proteins

Proteins provide support and structure to cells and tissues.

function of enzymes/catalysts (proteins)

Proteins speed up chemical reactions in the body.

function of transportation proteins

Proteins transport substances throughout the body or across cell membranes.

function of movement proteins

Proteins allow cells and body parts to move.

function of communication proteins

Proteins help cells communicate with each other, often by acting as receptors or signaling molecules.

function of defense proteins

Proteins help protect the body from harmful substances/pathogens, such as antibodies.

monomer of proteins & how are they connected?

amino acid joined by peptide bonds via dehydration synthesis rxns

amino acid structure

Amine group (-NH₂)

Acid group (-COOH)

H⁺

R group

Variable

enzymes lower ?

activation energy

primary protein structure

Continuous strand of amino acid bound together by peptide bonds.

ii.     Linear

iii.   Proteins do not exist as linear chains of amino acids > no function

Secondary structure of proteins

Patterns of hydrogen bonds that give either a twisty shape or a sheet shape.

1.     Twisty shape = alpha helix

2.     Sheet shape = beta-pleated sheet

protein tertiary structure

3D shape formed by two secondary structures

• fibrous

• globular

  

Fibrous Proteins

Strand-like

Hydrophobic

Stable

α-helices or β-sheets

Examples: Keratin, Elastin, Collagen

Globular Proteins

Spherical

Hydrophilic

Sensitive to environmental changes

both α-helices and β-sheets

Ex: Antibodies, Hormones, Enzymes

Proteins Quaternary Structure

• How more than one polypeptide chain fits together to form a functional protein.

• Not all proteins exhibit a quaternary structure only proteins made up of more than one polypeptide chain have quaternary structure.

protein denaturation

• Loss of their 3D shape > & function

• Caused by ↑ temperatures, ↓ pH (acidity), Chemicals

• Reversible if normal conditions are restored

• more common

Which type of protein (globular or fibrous) is more easily denatured?

Globular proteins because they fold into complex, compact shapes held together by weak, delicate bonds, shifts in temperature or pH easily disrupt their structure.

In contrast, fibrous proteins are highly resistant to denaturation because they form tough, tightly packed, rope-like structures stabilized by strong covalent cross-links.

structure of nucleic acid

C, H, O, N and P

monomer of nucleic acids

nucleotide

structure of nucleotide

Nitrogenous base

Phosphate group

Sugar (monosaccharide)

>Ribose or Deoxyribose

functions of nucleic acids

Store and transfer genetic information (DNA and RNA)

ATP

1.     The main high energy compound in our bodies (though there are others).

2.     Structure

a.     Ribose

b.     Adenine

c.     3 phosphate groups

• the bonds between the phosphate groups store tons of energy. When those bonds are broken via hydrolysis reactions, the energy that is released can be used to do cellular functions

1.     ATP is at the center of metabolism. It is the energy for our cells to carry out its functions

The ? of glucose via glycolysis (a type of hydrolysis reaction) is used to make ATP.

catabolism