Concepts to understand

Biochemistry is the chemistry of life

What are the properties of life in the context of biochemistry?

• Incredible complexity and organization
Information (genetical, structural) => __ entropy

Biomolecules - organelles — cells — tissues — organs — organisms

Homeostasis (body temperature, salts, voltage potentials, ...)

Metabolism (anabolism, catabolism, pathways)

Responsiveness to the environment

Growth & Reproduction
Adaptation, including genetically

The principles of biochemistry ar common to ___ living beings.

Biochemistry VS. Organic Chemistry

-Very __ range of temperatures
-Narrow range of pH
-Atmospheric pressure
-Water is the major ____ (versus a wide variety in organic chemistry)
-Carbon-based (limited choices of elements & molecules)

How does LIFE find solutions? ____

Life is ___ based

Why C?

• Four ___ bonds => diversity of 3D structures

• Stable double, triple bonds

• Forms/breaks bonds with _, _, & _

• Reversible oxidation/reduction

C-based molecules active under the ____ conditions

Alternatives to C?
B : 3 electrons; not stable
5 electrons; N-N-N => explosives
Si: Large radius => Si-Si is a weak bond
P : Not stable

Other elements of life

• Oxygen, hydrogen, nitrogen, phosphorus, sulfur are major elements

In addition to homo- (C-C), form heteronuclear bonds (C-O)

These covalent bonds can break and form

Several other elements are in small (trace) quantities

Examples: Ca2+ Mg2+ Fe2+ & Fe3+

Water is an essential solvent and ___
-->50-95 % (by body weight)
-->Unique properties: small size, chemical stability, low viscosity, polarity, melting & boiling points, ...

Four classes of biological macromolecules

WHat are the functions of each?

l. Carbohydrates = ____
ll. Lipids = ____
Ill. Nucleic Acids = ____
IV. Proteins = ____

Most of the biological macromolecules, except for lipids, are ___

Polymers are formed from like monomers

Depending on the polymer, different types of ___ bonds formed

Carbohydrates = Saccharides = ___

Example = Glucose
FG's = hydroxy & carbonyl

Glucose interconverts b/w alpha & beta forms and is in equilibrium in solution

Monosaccharides (single sugars)

Glucose, Fructose, Galactose

Disaccharides (2 sugars)

Sucrose = table sugar
Lactose
Maltose

Oligosaccharides

-consist of a few (3-10) monosaccharides

Polysaccharides

-are long polymers

What happens when you digest sugar?

-Ether bond breaks with the addition of water (____ reaction).

-Enzyme plays a key role.

Sugars/Carbohydrates - Function

• Energy source — e.g. glucose

• Structure — e.g. ___

• Part of another biomolecule:
v/ Nucleotides contain a sugar moiety
v/ Glycoproteins: ___ with covalently attached a carbohydrate

Glycolipids: lipids with ____ covalently attached

These complex molecules will be discussed later in detail

Protein is a polymer of ___ ___

• a-amino acids are the building blocks

• Peptides is < __ amino acids

• ____ is >50 amino acids

• A protein is one or more polypeptides

Amino Acids

• a-amino acids are building blocks of proteins

• In peptides, amino acids are covalently attached via ___ bonds

There are 20 standard a-amino acids in proteins

• Properties of amino acids and proteins are determined by the properties of the ___ ___ of the amino acids

• Amino acids can be grouped depending on the chemical properties of
their side chain: charge, polarity, acidity, interaction with water, ...

• Polypeptides are folded to form a functional 3D structure. In water hydrophobic residues are buried ___. -->Membrane proteins - opposite

Dehydration reaction forms the peptide (amide) bond

Nucleic Acids (DNA, RNA)

Nucleic acid is a polymer of ___ monomers

Nucleotides are formed from three functional groups:

1. Phosphate group (P)

2. A 5-carbon sugar: (R) Ribose, (D) Deoxyribose

3. Nitrogenous base: (A) Adenine, (G) Guanine, (C) Cytosine, (T) Thymine, (U) Uracil

Nucleic Acid Synthesis

NTPs (nucleoside triphosphates) are ___ building blocks

dNTPS (deoxynucleoside triphophates) are ___ building blocks

LIPIDS

Lipid molecules contain relatively large ___ fragments

___ : do not dissolve in water but do dissolve in non-polar solvents

Do NOT form ____

Simplest lipids are ___ ___

FAs consist of a terminal carboxyl group (___) and hydrocarbon tail or chain (___).

Glycerophospholipid

-Amphiphilic
-Form bilayers

Triglyceride (triacylglycerol, TAG, TG) is an ester-linked glycerol & 3 FAs

-FAt found in the ___

-Excessive calories are saved as __ ___ in the form of triglyceride

-Skin oil

-High levels in the blood may cause stroke, heart diseases, pancreatits, ...

Waxes

Steroids