Biomolecules Flashcards
Describe the structure of a water molecule
-One oxygen atom covalently bonded to 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 six 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?
Cohesion is 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 against the pull of gravity up the xylem.
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 which joins a monosaccharide to another molecule (usually another monosaccharide to form a disaccharide) It has the following structure
C C
\ /
O
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
-Made up of many alpha glucose molecules joined by either alpha 1-4 or alpha 1-6 bonds
-Highly branched
-Compact
Describe the structure of starch
-Made of amylose (joined by alpha 1,4 bonds) and amylopectin (joined by alpha 1,4 and alpha 1-6 bonds)
-Coiled are branched
Why is glycogen useful as a storage molecule in animals?
-It is highly compact
-It is highly branched so it can be broken down by enzymes easily for respiration
-It insoluble
What three elements are triglycerides made up of?
Carbon, hydrogen, and oxygen
Draw the structure of glycerol
H H H
| | |
H-C-C-C-H
| | |
OHOHOH
Describe the structure of a triglyceride
-One molecule of glycerol
-Attached to three fatty acid chains by ester bonds
-Fatty acid chains may or may not contain double bonds
Describe the structure of a triglyceride
-One molecule of glycerol
-Attached to three 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 and have the following structure
