Transcript Basic Biochemistry

Basic Biochemistry
Water, Carbon, and Functional Groups
Water

Abundance of water
makes Earth habitable

Unique properties
Water Molecules

Polar due to differences
in electronegativity

Hydrogen bonds form
Properties of Water



Cohesion
Adhesion
Surface tension
Properties of Water




(What is temperature?)
High specific heat
Evaporative cooling
Good solvent
Interactions with Water

Hydrophilic vs.
hydrophobic
Carbon



Can bond to 4 other
atoms
Carbon chains can be
long, be branched, or be
circular
Hydrocarbon chains
Functional Groups


Most commonly
involved in reactions
Types:


Hydroxyl, carbonyl,
carboxyl, amino,
sulfhydryl, and phosphate
Chart pg. 64-65
ATP


Adenosine triphosphate used for energy transfer
ADP + Pi ↔ ATP
Macromolecules
Review



What are the four essential macromolecules in
the cell?
What are their structures?
What are their functions?
Macromolecules



Can be 10,000s of atoms
Polymers: linked chain of monomers
Variation in sequence is major difference
Dehydration Synthesis



Removal of water to link
two monomers
Requires energy and help
of enzymes
Hydrolysis breaks bonds
(ex. Digestion)
Carbohydrates




Sugars and their polymers
Mono-, di-, and
polysaccharides
Monosaccharides (-ose) can
have three-seven carbons
Chain or ring forms
Carbohydrates


Glucose (C6H12O6) and Sucrose (C12H22O11) are most
common
Polysaccharide uses: storage or structure
Carbohydrates



Starch = helical polymer of glucose (in plants)
Glycogen = more branched; stored in
liver/muscle cells
Cellulose = most abundant organic compound


Never branched. Hydrogen bonding to nearby cellulose
molecules. Microfibrils are structurally strong.
Chitin = fungi structures; exoskeletons
Lipids



Fats, steroids,
phospholipids
Hydrophobic
Fats = glycerol (3-C
alcohol) and 3 fatty acids
(hydrocarbons)


Saturated vs. unsaturated
Primarily energy storage
Lipids

Phospholipids = glycerol + 2 fatty acids + phosphate


Partially hydrophilic, partially hydrophobic
Lipid bilayer membranes
Lipids

Steroids = four fused rings

Cholesterol, many hormones
Proteins




Most structurally complex
See chart pg. 78 for types
Enzymes catalyze reactions
20 different amino acids
combine to create a polypeptide
Proteins



Amino acids linked through
peptide bonds in unique
sequence
Proteins consist of multiple
polypeptides
Function relies on proteins
recognizing/bonding to other
molecules
Protein Structure

PRIMARY: amino acid
sequence

SECONDARY: α helix
or β pleated sheet due to
hydrogen bonding of CN backbone
Protein Structure

TERTIARY: interactions
between ‘R’ groups (ionic,
hydrogen bonds,
hydrophilic/phobic)

QUATERNARY:
multiple polypeptide
chains overlapping

Denaturing…
Nucleic Acids




DNA/RNA
Direct protein synthesis
Nucleotides 
polynucleotides
Pyrimidines (T, U, G) vs.
purines (C, A)
Nucleic Acids




Antiparallel double
helix
5’: phosphate
3’: C-OH
Replication,
transcription,
translation
Phosphodiester Bond
Overview

Higher levels of
organization result in
new, more complex
properties.

The structure of each
macromolecule relates
specifically to its
function.
Self-Quiz, Chapter 5
Macromolecules
1

Which term includes all
others in the list?
1.
2.
3.
4.
5.
Monosaccharide
Disaccharide
Starch
Carbohydrate
Polysaccharide
2

Which of the
following statements
concerning
unsaturated fats is
true?
1.
2.
3.
4.
5.
They are more common in
animals than plants.
They have double bonds I the
carbon chains of their fatty
acids
They generally solidify at room
temperature.
They contain more hydrogen
than saturated fats having the
same number of carbon atoms.
They have fewer fatty acid
molecules per fat molecule.
3

The structural level of a
protein least affected by
a disruption in hydrogen
bonding is the
1.
2.
3.
4.
5.
Primary level.
Secondary level.
Tertiary level.
Quaternary level.
All structural levels are
equally affected.
4

Which of the
following pairs of
base sequences
could form a short
stretch of a normal
helix DNA?
1.
2.
3.
4.
5.
5’-purine-pyrimidine-purinepyrimidine-3’ with 5’-purinepyrimidine-purine-pyrimidine5’
5’-A-G-C-T-3’ with 5’-T-C-GA-3’
5’-G-C-G-C-3’ with 5’-T-A-TA-3’
5’-A-T-G-C-3’ with 5’-G-C-AT-3’
1, 2, and 4 are all correct.
5

Enzymes that break
down DNA catalyze
the hydrolysis of the
covalent bonds that
join nucleotides
together. What
would happen to
DNA molecules
treated with these
enzymes?
1.
2.
3.
4.
5.
The two strands of DNA would
separate.
The phosphodiester bonds
between deoxyribose sugars
would be broken.
The purines would be separated
from the deoxyribose sugars.
The pyrimidines would be
separated from the deoxyribose
sugar.
All bases would be separated
from the deoxyribose sugars.
6

Which of the following is
not a protein?
1.
2.
3.
4.
5.
Hemoglobin
Cholesterol
An antibody
An enzyme
insulin
7

Which of the
following statements
about the 5’ end of a
polynucleotide
strand is correct?
1.
2.
3.
4.
5.
The 5’ end had a hydroxyl
group.
The 5’ end has a phosphate
group.
The 5’ end is identical to the 3’
end.
The 5’ end is antiparallel to the
3’ end.
The 5’ end is in the fifth
position on one of the
nitrogenous bases.