2.5 Carbohydrates

2.5 Carbohydrates

• Some Functions:– Quick fuel– Short-term energy storage– Structure of organisms– Cell to cell recognition

2.5 Carbohydrates

• Simple Carbohydrates

2.5 Carbohydrates

• Simple Carbohydrates

– Monosaccharides are sugars with 3 - 7 carbon atoms

2.5 Carbohydrates

• Simple Carbohydrates

– Monosaccharides are sugars with 3 - 7 carbon atoms

– Pentose refers to a 5-carbon sugar– Hexose refers to a 6-carbon sugar

2.5 Carbohydrates

Three ways to represent the structure of glucose.

2.5 Carbohydrates

• Disaccharides contain two monosaccharides.

2.5 Carbohydrates

• Polysaccharides are long polymers that contain many glucose subunits.

2.5 Carbohydrates

• Polysaccharides are long polymers that contain many glucose subunits.

– Starch is the storage form of glucose in plants.

2.5 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.

2.5 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.

2.5 Carbohydrates

2.6 Lipids

2.6 Lipids

• Some Functions:– Energy Storage– Found in the plasma membrane– Component of steroid hormones

Lipids do not dissolve in water

2.6 Lipids

• Some Functions:– Energy Storage– Found in the plasma membrane– Component of steroid hormones

Lipids do not dissolve in water

Lipids are electrically neutral

2.6 Lipids

• Fats and Oils

2.6 Lipids

• Fats and Oils

– Fats• Usually of animal origin• Solid at room temperature

2.6 Lipids

• Fats and Oils

– Fats• Usually of animal origin• Solid at room temperature

2.6 Lipids

• Fats and Oils

– Fats• Usually of animal origin• Solid at room temperature

– Oils• Usually of plant origin• Liquid at room temperature

2.6 Lipids

• Functions of Fats

2.6 Lipids

• Functions of Fats– Long-term energy storage– Insulation against heat loss– Protection of major organs

2.6 Lipids

Synthesis and degradation of a fat molecule

2.6 Lipids

Emulsification

2.6 Lipids

• Saturated and Unsaturated Fatty Acids

2.6 Lipids

• Saturated and Unsaturated Fatty Acids

– Fatty acids are hydrocarbon chains that end with -COOH.

2.6 Lipids

• Saturated and Unsaturated Fatty Acids

– Fatty acids are hydrocarbon chains that end with -COOH.

• Saturated fatty acids: No double covalent bonds between carbon atoms

• Unsaturated fatty acids: Double bonds between carbon atoms

2.6 Lipids

Saturated Fatty Acid

Unsaturated Fatty Acid

2.6 Lipids

• Phospholipids

2.6 Lipids

• Phospholipids

– Comprised of 2 fatty acids + a phosphate group

– Primary components of cellular membranes

2.6 Lipids

2.6 Lipids

• Steroids

2.6 Lipids

• Steroids

– All steroids have four adjacent rings.

2.6 Lipids

• Steroids

– All steroids have four adjacent rings.

– Examples:

Cholesterol Testosterone Estrogen

2.6 Lipids

2.7 Proteins

• Proteins have important functions in cells.– Proteins such as keratin and collagen have

structural roles.– Proteins are also enzymes that speed up the

chemical reactions of metabolism.– Proteins such as hemoglobin are responsible

for the transport of substances within the body.

– Proteins also transport substances across cell membranes.

2.7 Proteins

• Proteins have important functions in cells.– Proteins form the antibodies of the immune

system that defend the body from disease.– Proteins such as insulin are hormones that

regulate cellular function.– Contractile proteins such as actin and myosin

allow parts of cells to move and muscles to contract.

2.7 Proteins

• Proteins are comprised of amino acids.

2.7 Proteins

• Amino acids– Amino group (-NH2)

– Acidic group (-COOH)– R group (remainder)

2.7 Proteins

2.7 Proteins

• Peptides

– A polypeptide is a single chain of amino acids.

– A peptide bond joins two amino acids.

2.7 Proteins

2.7 Proteins

• Levels of Protein Organization

– The structure of a protein has three or four levels of organization.

– The final shape of a protein is very important

to its function.

2.7 Proteins

2.7 Proteins

2.7 Proteins

2.8 Nucleic Acids

• DNA (deoxyribonucleic acid)

2.8 Nucleic Acids

• DNA (deoxyribonucleic acid)

• RNA (ribonucleic acid)

2.8 Nucleic Acids

• DNA stores genetic information.

• DNA codes for the order of amino acids in a protein.

• RNA is an intermediary in the sequencing of amino acids into a protein.

2.8 Nucleic Acids

• Components of a nucleotide

– Phosphate– Pentose sugar– Nitrogen-containing

base

2.8 Nucleic Acids

DNA Structure

2.8 Nucleic Acids

2.8 Nucleic Acids

• ATP (Adenosine Triphosphate)

2.8 Nucleic Acids

• ATP (Adenosine Triphosphate)– A high energy molecule– ATP undergoes hydrolysis and energy is

released

2.8 Nucleic Acids