2- Biological molecules Flashcards
Why is water a polar molecule?
Partial negative charge on one side (O) and partial positive on the other (H)
What is specific heat capacity?
Energy needed to raise the temperature of 1 gram of substance by 1 degrees.
What is latent heat?
Amount of heat energy required to change 1 gram of solid water (ice) at 0°C to liquid water at 0°C
What is cohesion?
Attraction between molecules of the same type
Why is water a good solvent?
Many substances in biological reactions ionic so attracted to charges of water - Totally surrounded by water molecules
What is water when solid? What attributes?
Ice. Less dense as ice as molecules held further apart - forms 4 hydrogen bonds ,making a lattice shape
What are polymers?
Molecule made up of smaller molecules called monomers
What are monomers?
A molecule that can react with other monomers to form a polymer
Glucose is a monosaccharide with 6C. What is it?
Hexose monosaccharide
Which way round is the end bonds of alpha glucose?
H at top OH at bottom
Which way round is the end bonds of beta glucose?
OH at top H at bottom
Why is glucose soluble?
So it can be easily transported for energy consumption (bonds contain energy)
Ribose is a 5C monosaccharide. What is it?
Pentose monosaccharide
What elements are all carbohydrates made from?
Oxygen, Carbon and Hydrogen
What are monosaccharides joined by? What does this form?
Glycosidic bonds. Disaccharide.
How is a polysaccharide formed?
When more than two monosaccharides join together
What is a condensation recation?
The formation of a bond when water molecule is released
What is a Hydrolysis reaction?
When a glycosidic bond is broken by the addition of water
Where do cells get their energy from?
Glucose
What do plants store excess glucose as?
Starch
What is starch made of?
Glucose, amylose and amylopectin
What is structure of amylose?
Long unbranched chain of a glucose. Coiled and compact. Good for storage.
What is the structure of amylopectin?
Long branched chain of a glucose. Branches allow enzyme to break down faster for quick release of energy.
Is starch soluble or insoluble? Why?
Insoluble so doesn’t enter cells via osmosis and swell them
What is excess glucose stored as in animals?
Glycogen
What is the structure of glycogen?
Similar to amylopectin. Long branched chain of a glucose with more branches for faster energy release.
What is celluose made of?
Long unbranched chains of beta glucose.
What is cellulose linked by? Why is this good?
Linked by hydrogen bonds that form microfibrils to support the cells structure
What is a triglyceride?
A molecule of glycerol with 3 fatty acid tails
Which parts of a triglyceride are hydrophobic?
Fatty acid tails
How are triglycerides synthesised?
By the formation of ester bonds between fatty acids and glycerol
How are Ester bonds formed?
Condensation reaction
What is the difference between a saturated and unsaturated fatty acid?
Saturated, don’t have any double bonds between their carbon atoms and unsaturated do
What are phospholipids?
Similar to triglycerides, but one fatty acid tail is replaced by a phosphate group
Where are phospholipids found?
Phospholipid bi-layer
What do cell membranes control?
What enters and leaves the cell
What does hydrophilic mean? Give an example.
Having an affinity to water - phospholipid head
What does hydrophobic mean? Give an example.
Repelled by water - phospholipid tails
What does cholesterol do?
Regulates the fluidity of the membrane
What does cholesterol do in high temperatures?
Membrane becomes less fluid and more rigid
What does cholesterol do in low temperatures?
Increases membrane fluidity
What are proteins made up of?
One or more polypeptides
What is the difference between different amino acids?
The variable group
What is the primary structure of a protein?
The sequence of amino acids in the polypeptide chain
What is the secondary structure of a protein?
Folded into an alpha helix or beta pleated sheet
What is the tertiary structure of a protein?
Coiled and folded further into its final 3-D structure
What is the quaternary structure of a protein?
Made of several different polypeptide chains (haemoglobin)
What bond holds together the primary structure of protein
Peptide bond
What bond holds together the secondary structure of a protein?
Hydrogen bonds
What bonds hold together, the tertiary structure of protein
Ionic and disulphide
What bonds hold together, the quaternary structure of protein?
Peptide, hydrogen ionic, disulphide
What is the role of haemoglobin?
Carries oxygen in RBCs
Haemoglobin is a conjugated protein. What is a conjugated protein?
A protein with a non-protein group attached
Where is the hormone insulin secreted?
Pancreas
What does insulin do?
Helps to regulate blood glucose level
What does amylase do?
Catalyses the breakdown of starch
What is the structure of amylase?
A single chain amino acid with both a helix and b pleated sheet
What are 2 characteristics of fibrous proteins?
Insoluble and strong
Where is collagen found? What does it do?
Animal connective tissue. Increases rigidity.
Where is keratin found? What does it do?
Skin, hair and nails. Can be flexible or hard and tough.
Where is elastin found? What does it do?
Elastic connective tissue. Allows tissues to return to original shape and structure.
