Carbon and biological Macromolecules

Zakk DrummTorpey WhiteRyan O’Kane

Carbon Carbon forms bonds between other

elements to make compounds essential for life

The study of carbon compounds is known as organic chemistry

Carbon bonds Carbon has four valence electrons so it

can accept four more electrons when bonding

Each carbon atom makes four bonds Known as tetravalence Tetrehedral bonds have an angle of

109.5 degrees

Miller’s Experiment Miller set up an experiment to mimic

early earth

Bonds cont. Common carbon molecules

› Carbon dioxide- CO2› Urea- CO(NH2)2› Glucose- C6H12O6

Carbon Chains Carbon chains form the backbone of

living organisms Carbon chains vary greatly in size and

shape

Hydrocarbons Hydrocarbons are molecules that are

made up of hydrogen and carbon atoms.

Many organic molecules have long hydrocarbon chains, such as fats

Isomers Isomers are molecules with the same

formula but different shapes› Structural isomers have different covalent

arrangements of molecules› Geometric isomers have the same

covalent arrangements but different spatial arrangements

› Enantiomers are mirror images of each other.

Properties of molecules The properties of organic molecules not

only depend on the Skelton, but also on functional groups

Functional groups Functional groups are components of

molecules most commonly found in chemical reactions

The number and arrangement of each functional group gives each carbon chain unique properties.

Functional groups cont.

Functional groups ATP is a phosphate group responsible

for most of the energy used by cells ATP consists of an adenosine molecule

attached to three phosphate groups.

Biological molecules There are four classes of large

biological molecules, Lipids, proteins, carbohydrates and nucleic acids.

Macromolecules are large molecules composed of thousands of connected atoms.

The function of these molecules is directly related to their structure

Polymers Polymers are long chain like molecules

made from smaller building blocks Those building blocks are known as

monomers Three of the four classes of molecules

are polymers› Carbohydrates› Proteins› Nucleic acids

Hydrolysis and dehydration synthesis

Hydrolysis is the degradation of proteins by adding HOH

Dehydration synthesis is the synthesis of molecules by removing HOH

Carbohydrates Carbohydrates include sugars and their

monomers Monosaccharides are the simplest

sugars Disaccharides consist of two

monosaccharides And polysaccharides are made up of

many monosaccharides

Monosaccharides The formulas for monosaccharides are

usually multiples of CH2O Glucose is one of the most common,

and has a formula of C6H12O6

Monosaccharides Cont. Monosaccharides serve as fuel for cells

and are also used for building blocks of more complex sugars

Disaccharides Disaccharides are formed by brining

two monosaccharides together using dehydration synthesis.

The bond between the sugars is known as a glycosidic linkage.

Disaccharides cont.

Polysaccharides Polysaccharides are the polymers of

sugars Their functions are determined by the

sugars that construct them

Storage polysacchardies Storage polysaccharides are used for

storing energy in organisms Starch is the plant storage

polysaccharide Glycogen is the animal storage

polysaccharide

Starch Starch is made up of glucase

monosaccharides that have been linked together.

There are two forms, amylose and amylopectin, amylose is not branchd and amylopectin is branched.

Glycogen Glycogen is also composed entirely of

glucose Glycogen differs from starch in the fact

that it is more branched It is stored in the liver and muscle cells

of animals

Cellulose Cellulose is another polysaccharide

found in plants. It is also constructed from glucose but

uses the beta form and not the alpha form

This makes it indigestible by the human system

Cellulose V. Starch

Lipids Lipids are the only class of molecule

that does not form a polymer Lipids are hydrophobic molecules

because they consist mainly of carbohydrates that form covalent non-polar bonds.

Three main types, fats, phospholipids, and steroids

Fats Fats consist of glycerol and fatty acids Glycerol is an alcohol with three

carbons Fatty acids are long carbohydrate

chains.

Fats cont. Saturated fats have no double bonds

and are filled with a many hydrogens as possible.

Unsaturated fatty acids have double bonds and do not have all the hydrogens they can bond to

Phospholipids Phospholipids are lipids that have

hydro phobic fatty acid tails and a hydrophilic head.

They match up tail to tail to form a phospholipid bilayer

This bilayer makes up the cell membrane of most cells.

Steroids Steroids are lipids characterized by a

carbon skeleton consisting of four fused rings.

Cholesterol, a common steroid, is a component in animal cell membranes.

Proteins Protein functions include structural

support, storage, transport, cellular communications, movement, defense against foreign substances, and organic catalysts (enzymes).

Proteins are polymers called polypeptides.

Polypeptides are constructed using amino acids

Enzymes Enzymes are large proteins that act as

catalysts to speed up the rate of chemical reactions in cells

Enzymes are specific with molecules in the chemical reaction

Enzymes can perform their functions repeatedly

Polypeptides Polypeptides are polymers built from a

set of 20 amino acids The sequence of amino acids

determines a protein’s structure A protein’s structure determines its

function

Amino acids Amino acids are organic molecules with

carboxyl and amino groups attached to a central carbon

Amino acids differ in their properties due to variable side chains, called R groups

There are 20 different amino acids because there are 20 different side chains

Amino acids cont

Aminogroup Carboxyl

group

Amino acids cont.

Bonding of Amino acids Amino acids are linked by covalent

bonds called peptide bonds A polypeptide is a polymer of amino

acids Each polypeptide has a unique linear

sequence of amino acids that determines function

They are bonded through dehydration synthesis

Protein structure There are four levels of protein

structure, amino acid sequence, folds and helixes, secondary structure folding, bonding of tertiary structures.

Primary structures of proteins are the sequences of amino acids in the chain

Primary structure determines secondary structure

Protein Structure Cont. Secondary structure is on of two

things, beta pleated sheets and alpha helixes

These are determined by amino acids in the sequence

These are folded to form the tertiary structure

The tertiary structures are bonded to other tertiary structures to form quaternary structures

Structure Cont.

Sickle cell A slight change in a proteins DNA can

change its primary This can affect a protein’s structure

and ability to function. Sickle-cell disease, an inherited blood

disorder, results from a single amino acid substitution in the protein hemoglobin

Environmental factors in structure

physical and chemical conditions can affect protein structure

Alterations in pH, salt concentration, temperature, or other environmental factors can cause a protein to unravel and loose its native shape

This shape change is called denaturation A denatured protein is biologically

inactive

Determining structure Scientists use X-ray crystallography to

determine a protein’s structure Another method is nuclear magnetic

resonance (NMR) spectroscopy, which does not require protein crystallization

Bioinformatics uses computer programs to predict protein structure from amino acid sequences

Nucleic acids Nucleic acids are polymers called

polynucleotides Each polynucleotide is made of

monomers called nucleotides Each nucleotide consists of a nitrogenous

base, a pentose sugar, and a phosphate group

The portion of a nucleotide without the phosphate group is called a nucleoside

Nucleotide Monomers There are two groups of nitrogenous bases:

› Pyrimidines: C T (U) (cytosine, thymine, and uracil) have a single six-membered ring

› Purines: A G (adenine and guanine) have a 6-membered ring fused to a 5-membered ring

• In DNA, the sugar is deoxyribose • In RNA, the sugar is ribose.• Nucleotide = nucleoside + phosphate group.

Nucleoside = nitrogenous base + sugar