b1.1 - carbohydrates and lipids

4 classes of macromolecules

carbohydrates, lipids, proteins, nucleic acids

Why is life described as carbon-based?

All carbohydrates, lipids, proteins, and nucleic acids contain carbon.

How does carbon form bonds?

It shares its outer shell electrons to form covalent bonds.

How many covalent bonds can carbon form and with which elements?

Four covalent bonds, often with hydrogen, oxygen, nitrogen, carbon, and phosphorus.

What are common functional groups in biochemistry?

Hydroxyl (-OH), Amino (-NH₂), Carboxyl (-COOH), and Phosphate (H₂PO₄).

What reaction links monomers to form polymers?

Condensation reactions.

What are macromolecules made of?

Smaller molecules called monomers.

What breaks macromolecules into monomers?

Hydrolysis reactions, which break covalent bonds.

What happens during hydrolysis?

Water is split into two components and becomes part of the two smaller molecules.

What are digestive enzymes classified as?

hydrolyzing enzymes

Give an example of a hydrolysis reaction involving lactose.

Lactose → galactose + glucose.

What happens after digestion of monomers?

They are rebuilt into macromolecules by condensation reactions.

What is formed during condensation reactions?

A water molecule.

Glucose + galactose

lactose + water

Glucose + many glucose

starch + many water

Many amino acids

protein + many water

Phosphate group + pentose sugar + base

nucleotide + 2 water.

What is the covalent bond between two amino acids called?

A peptide bond.

What makes up overall metabolism?

The sum of condensation and hydrolysis reactions.

What type of sugar is ribose?

A pentose monosaccharide.

What type of sugar is glucose?

A hexose monosaccharide.

Why is glucose important?

It is used in respiration and photosynthesis.

What are key properties of glucose?

It is polar, stable, soluble in water, easily transportable, and releases a lot of chemical energy during oxidation.

How do plants store glucose?

As starch, a polysaccharide.

What forms amylose and what is its structure?

Carbon 1 bonded to carbon 4, forming a linear helix shape.

What forms amylopectin and what is its structure?

Links between carbon 1 and 6, forming branching structures.

Why are starch and glycogen good for storage?

they are insoluble in water

What is glycogen?

The animal equivalent of amylopectin, stored in liver and muscle tissue.

What type of glucose does cellulose use?

beta glucose

What structure does cellulose form and why?

A grid structure due to beta-1,4 bonds.

What is cellulose good for?

Providing stability, like in plant cell walls.

What molecules are included under lipids?

Fats, oils, waxes, and steroids.

Why are lipids hydrophobic?

They have many non-polar carbon and hydrogen bonds, making them insoluble in water.

How do lipids sometimes become soluble?

by conjugating with another molecule

How is a triglyceride formed?

Glycerol links to three fatty acid chains by condensation reactions.

How is a phospholipid formed?

Glycerol links to two fatty acid chains and a phosphate group by condensation reactions.

What are saturated fatty acids?

Fatty acids with single bonds between carbons, fully saturated with hydrogen; solid at room temperature (e.g., animal meats, butter).

What are monounsaturated fatty acids?

Fatty acids with one double bond between carbons; liquid at room temperature, used for energy storage by some animals and plants.

What are polyunsaturated fatty acids?

Fatty acids with more than one double bond; liquid at room temperature, used for energy storage by some plants.

What is adipose tissue composed of?

Cells that store fat in triglyceride form.

Where are thicker layers of adipose tissue commonly found?

In cold habitats, known as blubber.

draw an alpha glucose

draw a beta glucose

draw glycerol

draw a triglyceride

draw a phospholipid

draw a saturated fatty acid

draw a monounsaturated fatty acid

draw a polyunsaturated fatty acid

draw a ribose sugar

pentose monosaccharide

draw condensation reaction

Carbohydrate + Protein

glycoprotein

Lipid + Protein

lipoprotein

Carbohydrate + Lipid

glycoprotein

Functions of Conjugated carbon molecules

• cell signaling (cell to cell communication)

• transport

• adhesion

• catalysis

• recognition of self and non-self

long carbon chain length (lipids)

high melting point

few number of double bonds

high melting point

short carbon chain length

low melting point

many double bonds

low melting point

Steroid Hormones

• made by gonadal tissue

• Molecules produced by glands (variety) in the body. One group of hormones are called steroids. They are made up from a type of lipid: cholesterol. They regulate a wide variety of processes in the body