APBIO chap5 5.3

What are the one class of macromolecules that do not include true polymers and are generally not big enough to be considered macromolecules?

Lipids

What is part of the reason kids are hydrophobic?

Few polar bonds w/oxygen mostly consist of hydrocarbon with relatively nonpolar C-H bonds.

Fat is a glycerol joined to three fatty acids. How does this work?

glycerol is an alcohol- each of the carbons has a hydroxyl group. Fatty acid has a long carbon skeelton, usually 16 or 18 carbons long. the skeleton has lots of C-H bonds(nonpolar)

Why do fats separate form water?

because the water molecules hydrogen-bond to one another and exclude the fats.

What is the reaction that joins a glycerol and a fatty acid?

dehydration reaction

What is ester linkage?

It covalently bonds fatty acids(3) to the glycerol. ( between a hydroxyl(-OH) group and carboxyl group(COOH)

what does saturated mean in the term “Saturated fats“

the structure of the hydrocarbon chains of the fatty acids. If there are no double bonds between carbon atoms composing a chain, then as many hydrogen atoms as possible are bonded to the carbon skeleton. Such a structure is said to be saturated with hydrogen

what does unsaturated mean in the term “unsaturated fats“

has one or more double bonds, with one fewer hydrogen atom on each double-bonded carbon.(most of the time it creates a kink)

most animal fats are_____?

saturated

What fats are solid at room temp?

Sat. Animal fats, lard and butter

What fats are liquid at room temp?

plant and fish fats are referred to as oils—olive oil and cod liver oi

What is the major function of fats?

Energy storage

Humans and other mammals stock their long-term food reserves in ____?

adipose cells (see Figure 4.6a), which swell and shrink as fat is deposited and withdrawn from storage. In addition to storing energy, adipose tissue also cushions such vital organs as the kidneys, and a layer of fat beneath the skin insulates the body.

Because plants are relatively immobile, they can function with bulky energy storage in the form of ___?

Starch

Phospholipids are essential for cells because they are major constituents of ___ ______?

Cell membranes

phospholipid has __ fatty acids attached to glycerol

two

The third hydroxyl group of glycerol is joined to a _____ group, which has a negative electrical charge in the cell

Phosphate

The two ends of phospholipids show different behaviors with respect to water. The hydrocarbon tails are hydrophobic and are _____from water

excluded

the phosphate group and its attachments form a hydrophilic head that has an ____ for water.

affinity

When phospholipids are added to water, they self-assemble into a double-layered sheet called a “____” that shields their hydrophobic fatty acid tails from water

Bilayer

The phospholipid bilayer forms a _____ between the cell and its external environment and establishes ____ compartments within eukaryotic cells

boundary, seperate

Steroids are lipids that have a carbon skeleton that has ___ fused rings

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