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Oooh! Ahhh!
Particle Charge Symbol
Mass Location
Proton Positive P+ 1.67262158 × 10-
27 kilogramsIn the Nucleus
Neutron Neutral N 1.674927351(74)×10−
27
In the Nucleus
Electron Negative e- 9.10938188 × 10-
31 kilogramsIn orbits around the nucleus
Lewis diagrams show the symbol of the element and the number of electrons in the outer shell of an atom. Atoms have up to two electrons in the first orbit (shell), 8 in the second, 18 in the third.
Ionic Bonds Ionic bonds form
between metal and non-metal atoms, where one atom gives electron(s) and the other takes one/them, respectively.
Covalent Bonds Covalent bonds
form between two non-metal atoms, where electrons are shared and travel between the two nuclei.
Covalent Bonds Covalent bonds
bond can form unequally, where electrons spend more time with one atom than the other, forming a polar bond
Hydrogen Bonds Hydrogen bonding
occurs between polar molecules containing hydrogen. The slightly negative atom in one molecule (usually O or N) exerts a pull on a hydrogen atom in an adjacent molecule, creating a hydrogen bond.
Hydrogen Bonds The hydrogen bond is
easily broken but acts to hold molecules together.
A chemical reaction involves the rearrangement of chemical bonds with the release or absorption of energy
The process of Respiration uses the oxygen we breathe and glucose (a carbohydrate in our diet), to produce energy plus waste products of carbon dioxide and water. The chemical reaction is as follows:
Organic vs. Inorganic Molecules
size
structure
examples
organic inorganic
large small
simple – groups of 2 – 10 atoms only
complex – often involves rings or long chains
C6H12O6; C16H33COOH
NaCl; H2SO4; NaOH
hydroxyl
carboxyl
amino
structural formula example
What are functional groups?
groups of atoms that work as a unit and are often involved in bonding between molecules
– 0H
– COOH
– NH2
– O – H
– C – O – H \\O
– N – H \H
alcohols & sugars
fatty acids & amino acids
amino acids
Sources in your diet:
• Functions:
• Monomer of all carbohydrates
1) Energy source (e.g. glucose)2) Structure (e.g. cellulose)3) Cell to cell identification and communication
bread, pasta, fruit
monosaccharide
Take the following spheres from the box
6 black spheres 6 red spheres 12 yellow spheres
Make a stable structure with 5 black and one red sphere using only 6 springs
Now join the remaining 5 red spheres to 1 yellow sphere each & attach these hydroxyl groups, 1 per black sphere
Now fill in the remaining holes on the black spheres with the remaining yellow spheres
Now attach the 6th black sphere to a black sphere in the ring, beside the red sphere
C
CC
C
C
O
C
H
OH
H
OH
OH
H
HO
H H
HH
OH
Building a glucose structural formula
HO
OH
OH
OH
O
CH2OH
Simplified structural formula
Rules: do not draw the ring carbons, or any single hydrogens
Now get together with another group and place your glucoses side-by-side
Remove the –OH from one glucose and -H from the other glucose
Be sure to do this in such a way that you can repeat this process if a third glucose is added
You have made a disaccharide
Disaccharides: two monosaccharides joined by dehydration synthesis
glucose + glucose --> maltose + water
An ether bond formed (water removed from 2 hydroxyl groups)
Examples of disaccharides
glucose + fructose --> sucrose + water
glucose + galactose --> lactose + water
H HO
H2O +
Dehydration synthesis removes a water molecule, forming a new bond
Reactions:
• Hydrolysis adds a water molecule, breaking a bond
Starch:
Long chains of glucose
Found in potatoes
& grains
Glycogen:
Branched chains of glucose
Glucose stored in liver as glycogen
cellulose
Parallel chains of glucose with every second glucose inverted
Found in plant cell walls
Functions:
• Sources: meat, dairy, oils
long-term energy storage (triglycerides),
make cell membranes (phospholipids)
make hormones (steroids)
make waterproof coatings on plants and animals (waxes)
cushioning, protection, vitamin absorption
Take 3 black spheres,
3 red spheres
8 white spheres
Bond the three carbons together
Bond an oxygen to each carbon
Complete the bonding with hydrogens
You have built a Glycerol
Take 5 black spheres; 2 red spheres; 10 yellow spheres
build a chain of carbons
To the end carbon, double bond one oxygen and single bond one oxygen
Complete the remaining bonds with hydrogens
You have made a fatty acid
GlycerolH2COH
HCOH
H2COHFatty acid
Drawings of glycerol and fatty acid
Place the glycerol molecule beside the fatty acid
Remove the –OH from the fatty acid and the –H from one end hydroxyl group on the glycerol
Form a bond and assemble the other product
You have made a monoglyceride
glycerol fatty acid
monoglyceride
+H2O
What functional groups joins glycerol and fatty acid together?
What bond is formed between the glycerol and the fatty acid?
hydroxyl & carboxyl groups
An ester bond
How many water molecules are removed when making a monoglyceride?
-C-OH HOOC -
One water
Saturated fatty acids vs. Unsaturated fatty acids
Saturated fatty acid [Saturated with hydrogen]
Unsaturated fatty acid
Unsaturated cis-fatty acid
Unsaturated trans-fatty acid
Triglycerides:
monomers = glycerol and 3 fatty acids
3 water molecules are removed to make a triglyceride
Phospholipids: contain hydrophilic head (phosphate) and hydrophobic tails
(fatty acids)
Steroids: include the sex hormones and cholesterol; different structure than other fats
From a health point of view saturated fatty acids are associated with heart and health problems.
Also, trans- unsaturated fatty acids are also a problem for the heart.
What are essential fatty acids?
Why are they important in human diets?
Any fatty acids that humans can not make from other fatty acids are called essential fatty acids.
Without these fatty acids, people may have learning problems
and in extreme cases, get sick and die
Sources:
Functions:
1) Structural components of cells
2) Enzymes
3) Other (e.g. hemoglobin, keratin)
Meat, Dairy, Eggs, Tofu, Nuts
Monomer [building block] = amino acid
Take 2 black spheres; 2 red spheres
4 yellow spheres; 1 blue sphere
1 yellow or green sphere
Place the two carbons in a chain with the nitrogen [blue]
Place an oxygen and a hydroxyl group on the end carbon
Place two hydrogens on the nitrogen
Place a hydrogen and the yellow or green sphere on the central carbon
You have made an amino acid
There are 20 different amino acids.
They differ by their R-group
An R-group is the side chain and it affects bonding
Get together with another group and place the two amino acids beside each other
Remove an –OH from one amino acid and an –H from the other amino acid
Remember, you must be able to repeat this to add a third amino acid, so choose your removals carefully
You have made a dipeptide
H H O
N—C—C
H R OH
H H O
N—C—C
H R OH
+ H2O
amino acid + amino acid
peptide bond
H H O
N—C—C
H R
H O
N—C—C
H R OH
dipeptide molecule
Dipeptide: 2 amino acids joined together
peptide bond formed (water removed from amino and carboxyl groups)
Polypeptide: 3 or more amino acids joined together
Levels of protein structure:
Primary structure the order of amino acids
Keratin (in hair) is an alpha-helix
Fibroin (in spider web silk) is a beta-pleated sheet
Secondary structure:The two dimensional folding into alpha helix or beta-pleated sheet
Tertiary structure: Three-dimensional bends and kinks in secondary structure due to the interactions between R-groups
Quaternary structure:2 or more polypeptide chains join together to make a “globular” structure
Denaturation of Proteins
• a change in temperature, pH, or ionic concentration can change the 3-D shape of a protein and render it useless
• denaturation occurs by breaking the bonds (H, ionic, disulphide bridges) that give the polypeptide its tertiary structure
There are 20 amino acids, 8 of these can not be made from the remaining 12.
These 8 must be part of our diet and so they are called essential amino acids.
A complete protein is one that contains all 8 of the essential amino acids.
An incomplete protein is one that contains only some of the essential amino acids.
eg. of complete proteins -
meat
egg
milk
eg. of incomplete proteins -
Grains such as wheat & rice are deficient in lysine
Legumes such as beans, peas, soybeans and peanuts are deficient in methionine
Functions:
Sources:
Monomer:
DNA = genetic material (instructions to make proteins);
RNA = involved in making proteins;
ATP = energy for the cell
nucleotide (composed of a sugar, phosphate, and nitrogenous base)
there are no direct dietary sources
DNA
shape double-stranded
bases A, C, G, T
sugar deoxyribose
RNA
single-stranded
A, C, G, U
ribose
ATP-consists of a base (adenine); a sugar (ribose) and three phosphates
The function of ATP is to provide short term energy storage for the body to be used at any location.
The process of making ATP involves the equation:
ADP + Pi ATP + H2O
Since we are removing water, this is a dehydration synthesis
What type of reaction is this?
The process of releasing energy from ATP involves the
equation: ATP + H2O Pi + ADP
What type of reaction is this?
As we are breaking bonds with water this is a
hydrolysis reaction