Grade 12 Bio - Biochemistry

What are the types of carbohydrates?

Monosaccharides, disaccharides, and polysaccharides

What is a carbohydrate?

A biomolecule that contains C:H:O atoms in a ratio of 1:2:1, polymers, contains a long chain of subunits called monosaccharides linked by glycosidic bonds

What is the function of carbs?

They act as a sources of energy, building blocks for cells, and as surface markers for cell to cell identification and communication

What is a monosaccharide?

It is the simplest form of a carb, consisting of a single sugar unit; a building block for more complex carbs. Ex. glucose (most common, primary cell fuel, and when dissolved in water the hydroxyl on C1 can end up either above or below the ring making it beta/alpha) ,galactose (found in milk) and fructose (sweeter than glucose, found in fruit)

RATA summary of carbs

Carbs are sugar polymers with hydroxyl groups that make them water-soluble. Main functions include energy source (glucose) and energy storage (form of starch, plus structural support (cellulose in plant cell walls). Form glycosidic bonds through a dehydration synthesis reaction between the hydroxyl functional groups of two monosaccharides.

What is an isomer?

A molecule that has the samw composition as another, but a different arrangement of atoms.

What is a disaccharide?

A carb molecule that is made from two monosaccharide unitsW

What is the function of a dissarchiade?

Utilised as building blocks for larger molecules. The type of disaccharide formed is dependent on the monomers involved and their form (alpha/beta). Eg. maltose is formed via condensation rxn (dehydration syntheiss) this formed a glycosidic link)

What is a polyssacharide?

3+ monosaccharides linked by glycosidic linkages, utilised for energy storage and structual support. Ex starch, glycogen, cellulose, and chitin

What is starch?

A polysaccharide made from 2 to 6 thousand glucose molecules, is the energy storage molecule in plants, is a mixture of amylose (unbranced colid alpha glucose chain) and amylopectin (branced a-glucose chain)

What is glycogen?

A polysaccharide that functions as an energy storage molecule in humans and other animals. Made from approx 50 000 glucose monomers in chains with many branches.

What is cellulose?

A polysaccharide, functions as the structural component for plant cell walls, made of straight chain of b-glucose monomers with b1-4 linkages, forms bundles of fibres. We cannot digest this as humans lack the enzymes to break down b1-4 linkages.

What is chitin?

A polysaccharide that makes up the exoskeleton of insects and crustaceans. It contains a glucose-like monomer with a nitrogen group at carbon 2. It is also used to make a strong and flexible surgical thread.

What is a glycosidic bond?

A bond between two monosacharides, typically involving the hydroxyl groups.

What is a complex carbohydrate?

A molecule that is composed of hundreds to thousands of monosaccharides linked together

What is polymerization?

A process in which small subunits are linked to form a large molecule.

What is a monomer?

A small molecule that can bind chemically to other molecules

what is a polymer?

A large molecule that is formed when monomers link together chemically in a chain.

What is a protein?

A large molecule that consistes of many amino acid subunits that are joined together by peptide bonds folded into a specific 3D shape. It is involved in everything.

What is a nucleic acid?

A blueprint for proteins that are synthesized in cells; stores hereditary information

What is an amino acid?

A molecule that contains a carboxyl group and an amino group; serves as the monomer subunit of proteins

What is a peptide bond?

A covalent bond that links amino acids

What is a peptide?

A chain of amino acid subunits that are connected by peptide bonds

What is a polypeptide?

A peptide with more than 50 amino acids?

What is denaturation?

It is the loss of both the structure and function of a protein

What are the functions of proteins?

Each type has a unique function:

Enzymes: biological catalysts —> speed up rxn

Immunoglobins —? protect against cancerous cells/foreign microrganisms (eg. antibodies)

Protein Carriers —> transport materials through all membranes and through the body ( hemoglobin)

Structural Support —> eg. keratin in hair and nails, collages forms protein portion of bones, skin, and ligaments/tendons, fibrin helps blood clot

What are proteins? RATA

Proteins are amino acid polymers with peptide bonds, recognised by their amino & carboxyl groups and 3D shape. They do almost everything in cells—enzymes catalyse reactions, hormones signal, and structural proteins build and support the body.

How are proteins formed?

Formed via dehydration synthesis rxn between an amino group and a carboxyl group.

What are the polar amino acids?

Serine, thereonine, cysteine, thyrosine, asparagine, and glutamine.

What do acidic amino acid look like?

There is a carboxyl group on their R-group.

What do basic amino acid look like?

There is an amino group on its side chain.

What are non-polar amino acids?

Glycine, alanine, valine, leucine, isoleucine, methionine, phenylalanine, tryptophan, and proline.

What is the primary protein structure? RATA

It’s the unique linear sequence of its AA in each polypeptide chain. Changing even a single AA result = alter overall structure of protein (to some degree). The sequence of amino acids is determined by the nucleotide sequence of a specific gene. In protein with “x” # of amino acids, # of probablities is 20x. There is great diversity in the primary structures that can form, limitless.

What is secondary structure ? RATA

Most polypeptides possess portions that repeatedly coil/fold into patterns and contribute to the overall shape of a protein. This secondary structure is the result of H-bonding between the carboxyl and hydroxyl functiuonal groups between the two amino acids. The two types are alpha helix and beta pleated sheets.

What is alpha helix?

A tight coil produced by h-bonds that are repeated at the same distance in the amino acid chain. A type of secondary structure.

What is a beta pleated sheet?

H-bonds formed between parallel strtches of a polypetide. An type of secondary structure.

What is tertiary structure? RATA

The polypetide chain undergoes additional folding due to side chain interactions

What is quaternary structure?

2/+ polypeptide chains link together to form a final functional protein (ex. collagen/haemolobin which are composed of 4 polypeptides each consisting of 140+AA. Hold multiple polypetide chains together via h-bonds, polar/non polar interactions, and disulfide links.