Organic materials: Structure and function Flashcards
How many different types of amino acids are there?
20
What two groups forms an amino acid?
H2N (amino group) + COOH (Carboxyl group)
Define Zwitterion
A molecule that can have a positively and negatively charged group
What type of bond occurs between two different amino acids?
Peptide linkage/ amide bond
What is an amide group?
O (double bond) C - N - H
Define amphoteric
Able to react both as a base and as an acid.
In a basic solution, which amino acid group would donate an H+ ion to lower the pH of the solution to neutralize it
Carboxyl group
Describe the primary structure of a protein
- Held together by covalent bonds
- N terminus (left), C terminist (right)
- Chain of amino acids
Describe the secondary structure of a protein
- Hydrogen bonds occur in regular intervals, forming an alpha helix shape
- Segments of the polypeptide chain ( H bonds), fold = Beta pleaded sheets
Describe the tertiary structure of a protein
- 3D structure
- Influenced by the R chain (determines the type of bonding)
- Functional form of protein
Describe Quaternary protein structure
- 4D
- The manner in which subunits are arranged
A protein based catalyst is known as a…
Enzyme
What is the main purpose of an enzyme?
To lower activation energy
How does an enzyme work?
Substrate binds with the active site, however doesn’t take part in any chemical reaction
- What are the two types of enzyme models? 2. What are the two models differences?
- Lock and key, Induced fit
- Lock and key suggest the substrate fits perfectly into the active site (enzyme), whereas induced fit suggests the active site mold to the shape of the substrate
Define monomer
A molecule that can be bonded to other identical molecules to form a polymer.
Define
monosaccharide
- Simple sugars
- The simplest forms of sugar and the most basic units from which all carbohydrates are built.
What are the 3 main types of monosaccharides?
- alpha glucose
- beta glucose
- beta fructose
What’s the difference between monosaccharides and monomers
Monosaccharides are monomers, however, monosaccharides are carbohydrate specific
What is the difference between alpha and beta glucose?
- The orientation of the -OH group on carbon 1 (Alpha is a same-sided 1-4 hydroxyl groups, while beta refers to opposite-sided 1-4 hydroxyl groups)
- Beta glucose is soluble in water
How is a disaccharide formed?
Monosaccharides take part in a condensation reaction
What is the difference between disaccharides and monosaccharides?
Monosaccharides are only 1 glucose, where di is two
What are the different glycosidic linkages of a disaccharides?
Beta 1,4 and 1,6
Alpha can only do 1,4
What is a polysaccharide?
Lots of monosaccharides bonded together eg. Cellulose and starch
Describe the structure of cellulose
Straight chain, Beta-1,4-glucosidic linkage
Describe the structure of starch
Straight chain, Alpha-1,4-glycosidic linkage
What are two types/ variations of starch?
- Amylose
- Amylopectin
What is the differences between Amylose (1) and Amylopectin (2)?
(1) Alpha formation (coiled helix), straight chain, therefore harder to break the bond
(2) Highly branched (easier to break because water and enzymes can reach) due to -OH position, easier to break
What monosaccharides has a 5x carbon ring structure?
Glucose
What two molecules makeup triglycerides? What does it form?
- Glycerol
- 3x fatty acids
= 3x ester groups
What kind of reaction forms a triglyceride?
Condensation
What are fatty acids made up of?
Long carbon chain and hydroxyl group
What are the two types of fatty acids
Unsaturated and Saturated
What is the difference between saturated and unsaturated fatty acids?
unsaturated = double bonds (healthier ones)
saturated = single bonds (bad ones)
What is the formula for unsaturated/ monosaturated (1), and saturated (2) fatty acids
- CnH2n-1COOH
- CnH2n+1COOH
How does the position of a double bond in a unsaturated carbon effect the molecule?
- It can be classified further into different unsaturated carbons
- the name of the molecule changes depending on how far from the omega carbon it is
What is an ‘omega carbon’?
The carbon at the other end of the carboxylic group
What does fatty acid kinks result in?
Lowers the melting and boiling point of the molecule because intermolecular forces are weak*
How does the trans arrangement effect the molecule?
Increased melting and boiling point
What is essential and nonessential fats
essential = need to consume
nonessential = can be made in the body
What happens in base (NaOH) hydrolysis of triglycerides (soap)
Separation of the glycerol and fatty acid = soap
What parts of the lipids are (1)hydrophobic and (2)hydrophilic?
(1) end/tails (long carbon chain)
(2) heads (ionic)
What does the non-polar hydrocarbons react with
Non-polar substances ( fats and oils) **via dispersion forces
What part does the ionic end react with? What kind of bonding is this?
Water
Through ion-dipole bonding
What does amphipathic mean?
A hydrophilic and hydrophobic end
Micelles are the…
The little circle of the lipids trapping the oil in
What is hard water?
Lots of minerals in the water
How is ‘scum’ produced?
Fatty ions react with metal ions, therefore forming precipitates
What functional group is triglycerides from?
Ester
Define polymer and polymerization
Multiple monomers bonding together to form long strands
What are co-polymers?
Condensation polymers
What name is given to 4x ethene?
Polyethene
What kind of polymerization forms unsaturated organic molecules?
Addition
TRUE OR FALSE: When double carbon bonds break (ene) they form an (ane)
FALSE: its still an ethane
What does (1)LDPE and (2)HDPE stand for?
(1)Low Density Polyethene
(2)High Density Polyethene
What are the characteristics of LDPE?
- Formed in high temps and pressures
- Contains branches (therefore weak dispersion force)
- Low MP
- Bendy
What are the characteristics of HDPE?
- Formed in low pressure
- Long carbon chain (string intermolecular forces)
- High MP
- Hard
What are the characteristics of Thermoplastics?
- softened when heated (can be reshaped and recycled)
- They can bend due to their stronger INTRAmolecular bonds vs their INTERmolecular bond
What are the characteristics of Thermosetting?
- Burn (impossible to remold)
- Covalent bonds
- INTRA and INTER bonds are similar strength
What is crosslinking?
Intermolecular or intramolecular joining of two or more molecules by a covalent bond. eg. thermoplastics, elastomer, thermoset
What are the main factors effecting plastic properties?
- branching
- chain length
side groups - crystallization
What does polarity effect in polymers
- strength of intermolecular bonds
What kind of bond increases strength in polar molecules?
Hydrogen bonds or dipole-dipole bonds
How does carbon chain length effect intermolecular forces?
Longer chain = increased strength
Shorter chain = decreases strength
How does branching effect strength?
More branches reduce stacking = less strong
How do side groups effect strength?
Don’t allow strong intermolecular forces
What is an Isotactic polymers structure?
All methyl groups are found on 1 side = formation of crystalline (stronger)
What is an Atactic polymers structure?
Methyl groups are randomly distributed = no crystalline formation = weak, soft, low melting point
What is a Syndiotactic polymers structure?
Methyl groups alternate sides = crystalline regions, hard, strong, high melting point
What can can enhance polymers properties
Additives
What is the difference between crystalline and amorphous structure?
Crystallin has a regular arrangement, chain are compact
Amorphous has irregular arrangement patterns, overall weaker
