Exam 2

molecules made up of repeated subunits called monomers. The monomers are linked together by covalent bonds.

the bond between monomers broken by a water molecule with a hydrogen from water attatching to a monomer and the hydroxl attaching to the other. This breaks down large molecules. +H

monosaccharides

(condensation reaction) is a chemical process in which two molecules are joined together by the removal of a water molecule. This reaction forms macromolecules like carbohydrates, proteins, and nucleic acids. -H

amino acids

fatty acids

nucleotides

• Storing energy • A component of membranes • Cell communication

No. Lipids do not consist of repeating monomer units. Instead, they are composed of various types of molecules, such as fatty acids, glycerol, and other hydrophobic compounds, that do not link together in a repetitive manner.

Fats Phospholipids Steroids

the head is hydrophillic, the “legs” are hydrophobic

C and H

dehydration reaction occurs between each fatty acid and a hydroxyl.

Structure (similar to fats): Glycerol Two fatty acids Phosphate (negatively charged) Polar “Head”

a molecule that has both hydrophilic (water-attracting) and hydrophobic (water-repelling) regions.

a circle structure that forms when amphipathic molecules are added to water, they spontaneously arrange themselves into micelles to minimize the exposure of their hydrophobic tails to water.

At High Temperatures: Cholesterol helps prevent the membrane from becoming too fluid. It interacts with phospholipid tails, reducing their movement and keeping the membrane more stable. At Low Temperatures: Cholesterol prevents the fatty acid chains of phospholipids from packing too closely together, which helps maintain some fluidity and prevents the membrane from becoming too rigid.

reproduction water regulation salt regulation sugar biosynthesis

for all steroid hormones

create. for example, cholesterol is the precursor for steroids.

condensation, a chemical reaction where two molecules combine to form a larger molecule, typically with the release of a small molecule, such as water.

Steps: 1. Hydrogen (H+) is removed from the end of the polymer. 2. Hydroxide (OH-) is removed from the monomer. 3. The hydroxide and hydrogen combine to form a molecule of water. 4. The remaining monomer is covalently bonded to the polymer.

• Water (H2O) is added to the reaction site. • The covalent bond is broken at the site. • The polymer receives a hydrogen ion. • The monomer receives a hydroxide ion. • The two molecules are separated.

70-90% of water and the rest is organic compounds