Biological Molecules Flashcards
What is glucose + glucose
Maltose
What is glucose + fructose
Sucrose
What is glucose + galactose?
Lactose
What is the reaction when the monosaccharides join?
Condensation
What bond is formed?
Glycosidic bond
What breaks down a disaccharide into a monosaccharide?
Hydrolysis
What is the test for starch?
Add iodine and there should be a color change to blue black from red
What is starch made of?
Alpha glucose
What is the main role of starch?
Act like a storage molecule
How is starch adapted to its function?
It is insoluble (doesn’t affect water potential)
Compact so it can be stored in small spaces
Large so it doesn’t diffuse out of cells
It’s branches so it can be hydrolyzed easily for energy
How is glycogen different from starch?
Glycogen is shorter and more branched
What is cellulose made up of?
Beta glucose
How does cellulose differ from starch in bonding?
Adjacent beta glucose molecules are flipped 180 degrees
What is the function of cellulose?
Prevents the cell from bursting and provides rigidity
What is the difference in the OH groups in alpha and beta glucose?
In beta glucose they are on top and in alpha they are at the bottom
What is another difference between cellulose and starch? (Not alpha and beta)
Cellulose is straight and unbranched while starch is coiled and branched.
What is the role of glycogen?
Is the main carbohydrate storage product in animals
What are triglycerides made from?
Three fatty acids joined to a glycerol
What is the reaction that occurs when a triglyceride is formed?
A condensation reaction
What is the type of bond between a glycerol and a fatty acid?
An ester bond
What type of reaction breaks down a triglyceride?
Hydrolysis
What is the difference between saturated and unsaturated triglycerides?
A saturated has no double bonds and is a solid at room temperature because the molecules can pack together tightly.
An unsaturated has double bonds and is a liquid at room temperature because it doesn’t pack tightly together.
Why do triglycerides not form polymers?
They are not made of monomers and do not consist of repeating subunits.
What is a phospholipid made up of?
A phosphate head and two fatty acid tails
What are the properties of a phospholipid?
Hydrophilic head which interacts with water and a hydrophobic tail which moves away from water.
What is a phospholipid bilayer and why does it form?
Because of the way they interact with water the hydrophilic heads face the water and the hydrophobic tails face way from the water which forms a bilayer.
Draw a glucose monomer
See book
Draw a monomer of cellulose
See book
Why is water dipolar?
The oxygen molecule is slightly negative and the hydrogen is slightly positive.
Why is the specific heat capacity of water important for organisms that live in water?
A lot of energy is required to change the temperature so this means the temperature of the environment is stable and won’t change, it acts like a buffer.
What is the Structure of triglyceride
Glycerol and fatty acids
what is the test for a lipid?
Add ethanol and shake, solution will turn cloudy.
What are two types of proteins?
Globular and fibrous
What are proteins made from?
Amino acids
What is primary structure?
The sequence of amino acids making a polypeptide chain.
What is secondary structure? And what type of bonding is involved
The primary structure folds and coils into a helices and B pleated sheets
Hydrogen bonds
What is tertiary structure and what bonding is involved?
Secondary structure folds again to form a 3D shape with ionic,hydrogen and disulfide bridges
What is quaternary structure and what bonding is involved?
When more than one polypeptide chain is used and prosthetic groups are added.
What is an enzyme?
Biological catalyst (protein)
What makes an enzyme specific?
Has a specific active site can only bind with a complementary substrate which binds to make an enzyme substrate complex.
What is the effect of substrate concentration on enzyme activity?
The more substrate there is
The more successful collisions there are, the more chances of forming an ES complex
So the rate of reaction increases
It keeps going until all the enzymes are saturated and the rate is constant.
What is the effect of temperature on enzyme activity?
More kinetic energy,
The molecules move faster
Increased chance of a successful collision
Increased chance of forming an ES complex
Rate of reaction increases
Until optimum is reached
What happens when the optimum temperature is exceeded for enzymes?
The heat disrupts the H bonds in the enzymes tertiary structure so the active site changes shape and the substrate is no longer complementary so ES complexes can no longer form. the enzyme is denatured
What is the effect of ph on enzymes?
If the pH changes from the optimum then the bonds in the tertiary structure are disrupted and the active site changes shape, the substrate is no longer complementary so ES complexes won’t form.
What Are competitive and non competitive inhibitors?
Competitive - a substance with a similar shape to the substrate and a complementary shape to the active site. it blocks ES complexes from forming.
Non-competitive - binds to another site which is not the active site (allosteric) it causes the active site to change shape so ES complexes don’t form.
