Biomolecules Flashcards
Describe the structure of a water molecule
- One oxygen atom covalently bonded by two hydrogen atoms
-Oxygen is more electronegative than hydrogen, which leads to polar bonds and an uneven charge distribution
What is a hydrogen bond?
A type of strong intermolecular force. Hydrogen atoms which are directly covalently bonded to a highly electronegative atom (O, N or F) are attracted to highly electronegative atoms in other molecules.
What is a solvent?
Any substance which solutes can dissolve in to form a solution
State 6 important properties of water
-Acts as a solvent
-Acts as a metabolite
-High surface tension
-High specific heat capacity
-High latent heat of vaporization
-Strong cohesion and adhesion forces
Why is cohesion useful in biological systems?
It’s the main force supporting columns of water as they are pulled up the xylem in plants. The water molecules stick together as a constant column.
Why is adhesion useful in biological systems?
It allows water to move up the xylem against the pull of gravity.
What are carbohydrates?
Molecules that consist of carbon, hydrogen and oxygen only.
What are monosaccharides?
One individual monomeric sugar unit
What is a disaccharide?
Two monosaccharides covalently linked by a glycosidic bond.
What is a polysaccharide?
A polymer made of many monosaccharides covalently linked by glycosidic bonds.
What is a glycosidic bond?
A type of bond that joins a monosaccharide to another molecule (usually another monosaccharide).
What type of reaction forms a glycosidic bond?
A condensation reaction
Describe what happens in a condensation reaction
Two molecules are joined together and water is removed.
What type of reaction breaks a glycosidic bond?
A hydrolysis reaction
Describe what happens in a hydrolysis reaction
A molecule is broken apart using water.
Describe the structure of glycogen
What molecules and what bonds?
Made up of many alpha glucose molecules joined by either alpha 1,4 or alpha 1,6 bonds. Highly branched and compact.
Describe the structure of starch
What is it made of and what bonds?
Made of amylose (alpha 1,4 bonds) and amylopectin (alpha 1,6 bonds). Coiled and branched.
Why is glycogen useful as a storage molecule in animals?
It’s highly compact.
Highly branched so it can be broken down by enzymes easily for respiration.
It’s insoluble.
What 3 elements are triglycerides made up of?
Carbon, hydrogen and oxygen.
Describe the structure of a triglyceride
One molecule of glycerol attached to 3 fatty acid chains by ester bonds. Fatty acid chains may or may not contain double bonds.
What is an ester bond?
A type of covalent bond which is found in triglycerides and phospholipids. Ester bonds join the fatty acid tails to the glycerol molecule.
What is the difference between saturated and unsaturated fatty acids?
Unsaturated acids contain C=C double bonds.
Saturated fatty acids contain C-C single bonds.
