Biology exam #1

1-14=lecture 2, 15-25=Lecture 3, 26-35=Lecture 4, 36-56=Lecture 5, 57-84=Lecture 6

Eukaryotic cells

larger than prokaryotic cells

Prokaryotic cells

Larger than viruses

Viruses

larger than macromolecules

Macromolecules

larger than single atoms

atoms

Building blocks of life

The nucleus contains…

Protons and neutrons

Outside of the nucleus…

Electrons

Net charge of an atom is determined by

charge of the protons plus charge of electrons

ions

Atoms or molecules with a net ‘+’ or ‘-’ electrical charge

Ionic bonds

Are an electrostatic attraction between oppositely charged ions

Covalent bonds

Occur when atoms share electrons

Nonpolar covalent bonds

electrons are shared equally (EN difference less than 0.5)

Polar covalent bonds

electrons are not shared equally (EN difference greater than 0.5)

Electronegativity

Describes how strongly an atom attracts electrons

Functions of water

A medium for biochemical rxns, transport, temperature insulator

What kind of molecule is water

polar

How many polar covalent bonds does water have?

2

How many hydrogen bonds can water form?

4

Polar molecules in water

Hydrophilic, soluble in water

Nonpolar molecules in water

Hydrophobic, not soluble in water

Bronsted-Lowry definition of an acid

Donator of H+

Bronsted-lowry definition of a base

Acceptor of H+

As pH increases

H+ decreases, OH- increases

As pH decreases

H+ increases, OH- decreases

Condensation rxn

Link monomers together (covalent bonds) to form a polymer, with water as a product

Hydrolysis rxn

water is used to break polymers into their monomers

Monomer of carbohydrates

Simple sugars (monosaccharides)

Glycosidic linkages

The covalent bonds that link monosaccharides together

Disaccharides

Carbohydrates composed of two monosaccharides linked together

Oligosaccharides

Carbohydrates composed of 3-15 monosaccharides linked together

Polysaccharides

Carbohydrate macromolecules composed of more than 15 monosaccharides bonded together

Cellulose

structural polysaccharide of carbohydrates

Cellulose monomer

Beta-glucose

The bond that links cellulose monomers together

Beta-linkages

Cellulose degree of branching

Linear

Starch and glycogen

Polymers of alpha-glucose

Starch function

Energy storage in plants

Glycogen function

Energy storage in animals

Starch/glycogen monomers

alpha-glucose

Bonds that link starch/glycogen monomers together

Alpha-linkages

Starch degree of branching

Moderatley branched

Degree of branching in Glycogen

Highly branched

Enzyme, signaling molecule, signaling receptors, movement and structural

Protein functions

Monomer of proteins

Amino acids

Bonds that link AAs together

Peptide bonds

Peptides

AA polymers composed of 2-49 AAs

Polypeptides (proteins)

AA polymers composed of more than 50 AAs

Amino group, R-group, Alpha carbon, and a Carboxylic acid group

All AAs contain

R group

determines the function of an AA

the Amino group attached to the first AA added to the protein

Amino terminus

Carboxy terminus

CA group attached to the last AA added to the protein

Monomer of nucleic acids

Nucleotides

Covalent bonds that link nucleotides together

Phosphodiester bonds

Polymers of Nucleotides

DNA and RNA

Function of DNA

Store genetic information

Function of RNA

To regulate the flow of genetic information

Nucleotides contain

Phosphate group, Sugar, and a nitrogenous base (with R-group)

structural difference between RNA and DNA nucleotides

R group on DNA=Deoxyribose, RNA=Ribose

Sugar-phosphate backbone

strand of phosphate groups linked to sugars, 2 in DNA, 1 in RNA

The two sugar-phosphate backbones in DNA are linked together with…

Hydrogen bonds between nitrogenous bases

Charachteristics of lipids

Hydrophobic or amphipathic, contain non-polar hydrogen-carbon bonds

energy storage, membrane structure, cell signaling and protection

Biological roles of lipids

Types of lipids

Triglycerides and phospholipid

Triglyceride function

energy storage molecule

Phospholipid function

Primary component of the cell membrane

Monomer of triglycerides

1 glycerol molecule, 3 fatty acids

Glycerol molecule composition

3 carbon molecule that is the backbone of triglycerides

Fatty acid composition

carboxylic acid group, attached to a long hydrocarbon chain

Bonds that hold glycerol and fatty acids together

ester bonds

Fatty acid hydrocarbon chains can be either…

saturated or unsaturated

saturated fatty-acids

all C-C single bonds, long straight chains (Saturated with hydrogens)

C=C double bonds, lead to bends in the FA chain

Unsaturated fatty acids

Saturated fatty acids at room temp

Tend to pack well=solid

Unsaturated Fatty acids at room temp

Tend not to pack well, liquid at room temp

Cis double bonds in Fatty acids

Hydrgogens are on the same side of the C=C double bond

Trans double bonds in Fatty acids

Hydrogens are on the opposite side of the C=C double bond

Trans double bonds DO NOT significantly change…

the shape of the hydrocarbon chain

Trans double bonds in FAs come as a byproduct of….

Partial hydrogenation

Monomers of phospholipids

1 glycerol, 2 Fatty acid chains, 1 phosphate group (held together by ester bonds)

Phospholipids are…

Amphipathic

Phospholipids have a…head

Polar hydrophobic

Phospholipids have a…tail

non-polar hydrophobic

Phospholipids in an aqueous solution form…

Phospholipid bilayer, with a hydrophobic interior and hydrophilic exterior

PLBs are…

The structural basis for cellular membranes