Biological Molecules Flashcards
Definition of a monomer
Smaller repeating units; building blocks of polymers
Macromolecules are:
large molecules with 3D structures and functions
Like proteins
Monomers of proteins are:
Amino acids
An amino acid is made up of:
Four things to mention
- An amine group -NH4
- A central carbon
- An ‘R’ group
- A carboxyl group -COOH
A dipeptide is made up of what with what bond?
- Two amino acids
- A peptide bond
Polypeptide are
Dipeptides joined together by a peptide bond
Polypeptide are
Dipeptides joined together by a peptide bond
What is the variable ‘R’ group?
It’s the part of the amino acid that determines how the amino acid will interact in the environment and with other amino acids
Amino acids are linked together with what reaction to form what bond?
- Condensation reaction
- Peptide bond
How many amino acids are there? How many are essential?
- 20 amino acids
- 9 essential
How many stages of folding can a protein go through?
Four
Primary, secondary, tertiary and quaternary
What happens in the primary structure?
The amino acids bond together with a peptide bond to form a polypeptide chain
What happens in the secondary structure?
Hydrogen bonds form between neaby amino acids between the amine and the carboxyl groups within the chain
This folds the chain
What happens in the tertiary structure?
More bonds occur such as:
- Disulphide bonds
- Ionic bonds
- More hydrogen bonds
- Polar interactions
This further folds the chain into a 3D shape
What happens in the tertiary structure?
More bonds occur such as:
- Disulphide bonds
- Ionic bonds
- More hydrogen bonds
- Polar interactions
This further folds the chain into a 3D shape
What happens in th quaternary structure?
Multiple polypeptide chains are bonded together to form something much more advanced and specific
Not all proteins have to have a quaternary structure
What are the two types of proteins?
Globular and Fibrous
What is the most abundant molecule?
Carbohydrates
Monomers of polysaccharides are?
Monosaccharides
Monosaccharides are bonded together through what reaction with which bond?
- Condensation reaction
- Glycosidic bond
The monomers for sucrose are?
Glucose and fructose
The monomers for lactose are?
Glucose and galactose
Monomers for maltose are?
Glucose and Glucose
Glucose is classified as a monosaccharide
Two isomers of glucose are?
Isomers are compounds with the same formula but different arrangement
A-glucose
B-glucose
How is a-glucose structured?
As a coil
How is b-glucose structured?
Like a zigzag
Why are carbon-containing molecules classed as organic molecules?
They easily bond with eachother and create a strong backbone for other molecules to add on
Test for proteins and result?
- Biuret test
- Blue to violet
Test for reducing sugars and result?
All monosaccharides and some disaccharides are reducing sugars
- Benedict’s test
- Blue to brick red
Test for polysaccharides and result?
Basically the Benedict’s test with extra steps
Polysaccharides aren’t reducing sugars, so we have to break them down into them for the test to work
- Put small amount of sample in test tube
- Add HCL and boil for 1 minute- to hydrolyse(split up the saccharide)
- Add sodium hydrogen carbonate (to neutralise)
- Put into water bath for 5 minutes
- Positive test = brick red solution
Why is glucose stored as glycogen in humans?
- Glucose is very reactive on its own - can interfere in reactions
- Will also affect water potential
How is glucose stored in humans and plants?
- Glucagon in humans
- Starch in plants
Lipids aren’t solube in water but are soluble in?
organic ssolutions such as acetone or alcohols
Can lipids dissolve in water?
No - they are hydrophobic
What is a fatty acid?
A chain of 4-24 hydrocarbons and a carboxyl group
Lipids are held together using what bonds?
Ester bonds
What do catabolic reactions do?
Break larger molecules into smaller ones
What do anabolic reactions do?
Build larger molecules from smaller ones
Monomers of lipids
Fatty acids and glycerol
Found most commonly in the form of triglycerides
