BIOCHEM exam 1

What is the polymer of Amino Acids?

Proteins

What is the polymer of sugars?

Carbohydrates

What is the polymer of Fatty acids?

N.A!!

What is the polymer for Nucleotides?

DNA and RNA

Properties of amino acids and proteins are determined by?

the properties of the side chain of the amino acid

alpha-amino acids are building blocks for

proteins

Amino acids are made up of what two groups?

Acidic group and amino group

What are polypeptides?

>50 amino acids

Protein is one or more...

polypeptides (made up of amino acids)

Amino acids in peptides are covalently attached via

peptide bonds

Beta-alanine and gamma-amino acids _____ incorporated into proteins but serve other functions

ARE NOT

Beta-alanine

precursor of an important metabolic product

Gamma-aminobutyric acid (GABA)

is a neurotransmitter

Sugars have what two groups?

alcohol and carbonyl groups

Carbohydrates are composed of

sugars

monosaccharides contain

many sugars covalently linked (starch, cellulose, and glycogen)

What is the function of sugars/carbohydrates?

1. can be an energy source
2. can be for structure
3. can be part of another biomolecule

Fatty acids ______ form polymers

DO NOT

Most fatty acids are incorporated into

Lipids

alkyl group

a long hydrocarbon chain with C's and H's

The alkyl group is ______

hydrophobic (insoluble in water)

glycerol

a three carbon molecule with alcohol groups

glycerol is an important component of

lipids

Triacylglycerol

each alcohol of glycerol reacted with a fatty acid to an ester linkage (has 3 fatty acids)

Phosphoglycerides

two alcohol groups of glycerol reacted with fatty acid and one alcohol reacted with another functional group

what are the three parts of a nucleotide

1. 5 carbon sugar (ribose or deoxyribose)
2. A nitrogenous base
3. Phosphate group

purine

2 rings with N
-Adenine and Guanine

Pyrimidines

One ring (6 carbons) with N
-Thymine, Cytosine, and Uracil

What are the uses for nucleotides?

1. ATP: energy storage- high energy phosphate bonds can be broken to release energy
2. Building blocks for DNA and RNA- linear polymers with nucleotides covalently linked by phosphodiester linkages

Nucleophilic substitutions

nucleophile attacks electrophile, displaces leaving group

Elimination reaction

atoms lost, form double bond

Addition reaction

2 reactants combine to form 1

Isomerization

change order, no gain or loss

oxidation

transfer of electrons
- gains O or loses H

Reduction

transfer of electrons
-loss O or gains H

Hydrolysis rxn

-where O on a water molecule acts as the nucleophile
-electrophile is often carbonyl carbon of an ester, amide, or anhydride

Anhydride

molecule with two carbonyl groups linked via oxygen

NAD+ is the ______ agent

Oxidizing

energy

capacity to do work

when an electron is transferred, ______ is released

energy

which yields more energy, fatty acids or sugar?

-fatty acids yield more energy
-more reduced molecule (the more H's) the more energy it has

3 types of Metabolism pathways

1. Metabolic
2. Energy transfer
3. Signal transduction

Two types of metabolic rxns are

1. anabolic pathway
2. catabolic pathway

Anabolic pathway

biosynthetic- uses energy

Catabolic pathway

degradation- some release energy

Energy Transfer

Captures energy and transforms into a usable source

Signal Transduction

receive and respond to signals

What are the 3 steps in signal transduction?

receive, transduce, and respond

_____ are the basic unit of life

cells

Prokaryotes

-lack a nucleus
-single celled
-two classes

What are the two classes of prokaryotes

bacteria and archaea (extremophiles)

Eukaryotes

-have a nucleus
-can be multicellular

Biological membranes

-provides a selective physical barrier
-hydrophilic and hydrophobic components are important for organization

Lipid bilayer

organized through non-covalent interactions

membrane proteins

proteins associated with the membrane

Integral proteins

embedded in membrane

Peripheral proteins

attached to the surface of the membrane

Is the plasma membrane in Prokaryotes or Eukaryotes?

both

Is the nucleus in Prokaryotes or Eukaryotes?

Eukaryotes

Are membrane bound organelles found in Prokaryotes or Eukaryotes?

Eukaryotes

Are non-membrane bound organelles found in Prokaryotes or Eukaryotes?

Both

Is cell walls found in Prokaryotes or Eukaryotes?

Prokaryotes and maybe Eukaryotes

Prokaryotes are ______ for support

semi-rigid

peptidoglycans

short peptides linking long carbohydrate chains (provides strenght)

Gram +ve

peptidoglycan layer outside plasma membrane

Gram -ve

peptidoglycan layer is between (periplasmic space)
-stain can't get in because it's inside

glycocalyx

proteins and polysaccharides that are secreted and can form capsule or biofilm

Plasma membrane

physical barrier

Cytoplasm (prokaryote)

inside the cell

DNA (prokaryote)

genetic material
-circular DNA chromosome, attached to plasma membrane

Plasmids are in _____

prokaryotes

Plasmids

additional small circular DNA molecules
- can provide selective advantage

Pili and Flagella

structures on the surface of the prokaryote
Pili: attach to food or allow conjugation
flagella: movement

Endoplasmic Reticulum (ER)

interconnected membranous tubules and vesicles

RER

-has ribosomes bound
-makes proteins to go to the surface or be secreted

SER

-store Ca2+
-synthesis of some lipids, biotransformation in liver

Golgi

-stacks of flattened tubules
-processing and packaging of cell products to secrete and deliver to the surface (exocytosis)

Exocytosis

moving outside cell

What is the flow of the ER and Golgi

ER to "cis" Golgi to "trans" Golgi to vesicle to membrane

Vesicle

-for transporting material to the surface or outside the cell (called exocytosis)
-and for transporting material from the cell surface into the cell (endocytosis)

Lysosomes

for degradation
-vesicles fuse to lysosome for destruction of contents

Nucleus

has a nuclear envelope
-double lipid bilayer
-connected to ER

nucleolus

large dark staining spherical structure
-rRNA synthesis and ribosome assembly occur here

nuclear pores

large complex regulates entry and exit from nucleus

mitochondria

sites of aerobic metabolism
-oxygen dependent synthesis of ATP

Peroxisomes

small spherical membranous structures
-degrade fatty acids, synthesize some membrane proteins and degrade purine bases

Hydration

water surrounding other molecules to dissolve

Water has what type of geometry?

Tetrahedral geometry (bent shape)

Which part of water molecule has partial negative and positive charge?

O= partial negative
H= partial positive

Dipole

a molecule with charges that are separated so one end is negative and the other end is positive
-in electric field, dipoles are oriented to all face the same way

Which bond is stronger, covalent or Hydrogen bonds?

Covalent is stronger than H bond

How many hydrogen bonds in one water molecule?

4 Hydrogen bonds

The direction of H bond is important for______

strength

Strongest Hydrogen bonds are when they are ______

colinear (H|||O)

Water has a high _________

dielectric constant

dielectric constant

capacity to reduce electrostatic attractions between charges

_______ interactions drive protein folding

hydrophobic

amphipathic

part of the molecule is hydrophilic and part of the molecule is hydrophobic

What molecule is amphipathic?

fatty acids

Osmosis

spontaneous passage of water (solvent) through a semi-permeable barrier