Bio ws 3

Distinguish given structures of alpha and beta forms of glucose. Which of these occur in amylose, amylopectin, cellulose, glycogen?

-Alpha has the OH on the first carbon on the bottom -Glucose has the OH on the first carbon on the top -Amylose (unbranched) has alpha -Amylopectin has alpha -celluose has beta -glycogen has alpha

Explain dehydration (condensation) reactions as well as hydrolysis reaction in the context of formation and breakdown of biological molecules in cells.

-Dehydration is when two monomers come together and release a water molecule. Monomers are connected by a reaction in which 2 molecules are covalently bonded to each other, with the loss of a water molecule. -Hydrolysis is the breakdown of monomers with the addition of a water molecule. with a hydrogen from water attaching to one monomer and the hydroxyl group attaching to the other.

How many molecules of water are needed to completely hydrolyze a polymer that is ten monomers long?

9

What is a glycosidic linkage?

A covalent bond formed between two monosaccharides by a dehydration reaction

Explain the difference between a fat and a fatty acid.

A fat is composed of a glycerol and fatty acids. GLycerol is an alcohol. A fatty acid has a long carbon skeleton and the carbon at one end of the skeleton is part of a carboxyl group.

What glycosidic linkages are present in starch, glycogen, cellulose, maltose? Name the two types of starch

Alpha (1, 4) in all except cellulose - Beta (1,4)

How does the chemistry of oil containing cis-fats change during artificial hydrogenation?

Artificial hydrogen chemical converts cis fats to saturated fats. A by product of this is production of a small amount of trans fats.

A dehydration reaction joins two glucose molecules to form maltose. The formula for glucose is C6H12O6. What is the formula for maltose?

C12H22O11

What is the chemical formula of glucose? Draw a glucose molecule and number the carbons in the linear and ring forms of glucose

C6H12O6, -spiral

What are the four main classes of large biological molecules? Which class does not consist of polymers?

Carbohydrates, lipids, proteins, and nucleic acids. Lipids.

Explain why lipids are not considered polymers.

Lipids tend to be large, single molecules with no obvious repeating pattern. Because they are not made up of identical smaller molecules that combine to form a bigger one. Polymers are made up of monomers attached to each other.

Why do phospholipids in cell membranes exist as a bilayer?

Phospholipids are amphipathic - they contain polar heads and nonpolar tails. Inside of cells is aqueous so is outside. In the bilayer form the nonpolar parts can be together and polar parts of the phospholipids can interact with water inside and outside cell.

Explain how lipids are defined as a chemical group (i.e.: soluble in organic but not aqueous solvents).

They mix poorly with water

Explain why can we digest some types of sugars but not others. Give examples

We can't digest cellulose because the enzymes that break down alpha linkages can't break down beta linkages due to the different shapes of these molecules

Distinguish the basic structure of a steroid and how steroids may occur as components of membranes.

a carbon skeleton consisting of 4 fused rings. ex cholesterol is in membranes

Branching is seen in which polysaccharides? What carbons are involved in this branch point?

amlyopectin, 1-6

Determine why some triglycerides are liquid at room temperature and some solid.

depending on if they are composed of saturated fats or not. Solid= saturated liquid =unsaturated

Identify structures of triglycerides and phospholipids. Label the ester linkages between fatty acids and glycerol formed by condensation reactions.

phospholipids are similar to fat molecules but have only 2 fatty acids attached ti glycerol rather than three & the third hydroxyl group is attached to a phosphate group.

Describe how phospholipids self-organize into bilayers to make a membrane (and micelles, if desired) that possess varying membrane fluidity.

phospholipids have hydrophobic tails and hydrophilic heads. tails go on inside and head on the outside.

What are some examples of structural and storage polysaccharides? What are their functions?

storage polysaccharides are amlyopectin, amylose, glyogen. -cellulose and chitin are structural polysachharides. They

Describe the components of triglyceride, including saturated and unsaturated fatty acids, as well as different geometric isomers of unsaturated fatty acids.

triglycerides are 3 fatty acids linked to a glycerol by a ester linkage. Unsaturated fats have a double bond in the hydrocarbon chain and saturated fats don't. Cis bonds for unsaturated fats have double bonds that create a kink (bending)