Biomolecules

Organic compounds of life

TEKS• 9A: Students will…

Compare the structure and function of different types of biomolecules, including carbohydrates, lipids, proteins, and nucleic acids

• 9D: Students will…

Analyze and evaluate the evidence regarding formation of simple organic molecules and their organization into long complex molecules

Bio(macro)molecule

•A biomolecule (or macromolecule) is a large, complex molecule made up of repeating subunits

–The repeating subunits are known as monomers (mono = one)

–The large, complex molecule (ie: the biomolecule) is also known as a polymer(poly = many)

• LipidsCarbohydrates Lipids

Proteins Nucleic Acids

The Chemicals

of Life

CARBOHYDRATES• Elements: carbon, hydrogen, and oxygen (CHO)

• Elements are found in a 1:2:1 ratio (C=O)

• Monomer subunit: saccharides (different types of sugars)

• Look for: a CHO structure with #carbons = #oxygens

CARBOHYDRATES• Examples

• Sugars – fruits and vegetables

• Starches – bread, pasta, potatoes, and rice

• Glucose

• Functions

• Immediate energy

• Cell walls are composed of cellulose (chains of glucose) for strength and stability

• Found in cell membranes (used for signaling)

LIPIDS• Elements: carbon, hydrogen, and oxygen (CHO)

• Number of carbons > number of oxygens (C>O)

• Monomer subunits: fatty-acid chains and glycerol

• Look for: a CHO structure with #carbons much higher than the #oxygens

• Examples:

• Fats (butter)

• Oils (vegetable, olive, etc)

• Waxes (like candles or the coating on leaves)

LIPIDS• Functions

• Long-term energy storage (MUCH more energy than carbs); good for hibernation and warmth

• Important component of the cell membrane(phospholipids); keeps the inside & outside of the cell separate

• Steroids (like cholesterol and hormones)

• Protects against water loss

PROTEINS• Elements: carbon, hydrogen, oxygen, nitrogen, &

sometimes sulfur (CHON(S))

• Monomer subunits: amino acids bound by PEPTIDE bonds

• Look for: A structure with nitrogen, but no phosphorous

• Examples

• Meat

• Eggs

• Nuts

• Beans

PROTEINS• Functions

• *Enzymes, which speed up chemical reactions

• *Regulates hormones and reactions

• Component of the cell membrane (used for transport)

• Skin/hair/ nails

• Muscle movement

PROTEINS• Levels of structure (folding)

• Primary – amino acids

• Secondary – alpha helix or beta pleated sheet

• Tertiary – globular (ex: hemoglobin)

• Quaternary – 2+ proteins joined together

NUCLEIC ACIDS• Elements: carbon, hydrogen, oxygen, nitrogen, and

phosphorus (CHONP)

• Monomer subunit: nucleotides

• Look for: phosphorous

• Uses: Store and transmit genetic information

• Examples

• DNA – the genetic material that is passed from parent to offspring

• RNA – plays important role in the production of proteins

Food, Calories, and Energy

• Carbohydrates, lipids (fat), and protein are the three main sources of kilocalories

– 1 kilocalorie = 1 Calorie

– A calorie is a unit of energy specifically, the energy needed to raise the temperature of 1 gram of water by 1 degree Celsius

• Your body transforms these sources into components used in cellular respiration, the process which creates ATP

– ATP is the form of energy used by your body

How Polymers Become Monomers

• Hydrolysis

– Water is added to a polymer to divide it into its monomers

– This occurs during digestion• Carbohydrates are broken down into monosaccharides

• Lipids are broken down into fatty acids and glycerol

• Proteins are broken down into individual amino acids

• Nucleic Acids are broken down into nucleotides

How Polymers Become Monomers

How Monomers Become Polymers

• Dehydration synthesis: water is removed when two monomers come together to form a polymer

• This occurs when your body takes the monomer products from digestion and uses them to create new biomolecules for your use

– Monosaccharides are bonded into new carbohydrates

– Fatty acids and glycerol are bonded into new lipids

– Amino acids are bonded to make new proteins

– Nucleotides are bonded to make new nucleic acids

How Monomers Become Polymers

HO HO HH

H2O

HO H

Structure and Function

• The structure of a biomolecule determines it’s function

Example: Carbohydrates

• Glucose, Galactose, and Fructose have the same chemical formula (C6H12O6), but the atoms are arranged differently

• Since they have different structures, they also have different functions• Glucose is the immediate source of

energy for cellular respiration• Galactose enables the mammary glands

to produce lactose (breast milk)• Fructose is used for preventing

sandiness in ice cream

Structure and Function

• The structure of a biomolecule determines it’s function Example: Lipid

Structure and Function

• The structure of a biomolecule determines it’s function

Example: Protein

Structure and Function

• The structure of a biomolecule determines it’s function

Example: Nucleic Acids

• DNA and RNA have different structures• Number of strands (double vs. single)• Type of sugar (ribose vs. deoxyribose)• Bases (ATCG vs. AUCG)

• Since they have different structures, they also have different functions• DNA is the genetic material that gets

passed from parent to offspring• RNA decodes the DNA and turns it into

protein