Molecules of life

A water strider can skate on the surface of a pond because:

• covalent bonds result in water cohesion

• hydrogen bonds result in water cohesion (surface tension)

• water striders have adapted to take advantage of water cohesion

• low surface tension of water

Tags

NGSS.HS-LS4-4

Attractions between water molecules are called

• Covalent bonds

• Ionic bonds

• Polar bonds

• Hydrogen bonds

Water is polar because...

• The unequal distribution of electrons gives the water molecule a slight negative charge near its oxygen atom and a slight positive charge near its hydrogen atoms.

• The molecule has two poles, at which the it is colder than other regions of the molecule.

• The unequal sharing of electrons gives the water molecule a slight negative charge near its hydrogen atoms and a slight positive charge near its oxygen atom.

• The water molecule is neutral.

Why does ice float?

• As water freezes, it expands and its density decreases.
• As water freezes, it takes up more hydrogen from the atmosphere, causing it to have a greater buoyancy.
• As water freezes, air becomes trapped between the hydrogen bonds of water molecules.
• As water freezes, it takes up more oxygen from the atmosphere, causing it to have a greater buoyancy.

What property of water makes it the 'universal solvent'?

• it is a polar molecule
• it is an ionic compound
• it contains hydrogen bonds
• it steals electrons from other atoms

Tags

NGSS.HS-PS1-2

Name the structure shown in the diagram.

• β-glucose

• α - glucose

• amino acid

• fatty acid

Diagram shows the structure of polysaccharide. Name the polysaccharide.

• Amylose

• Amylopectin

• Glycogen

• Cellusose

Which type of lipid is this?

• unsaturated fat

• triglyceride

• phospholipid

• steroid

Triglycerides are formed by

• Hydrogen bonding

• Covalent bonding

• Ester bond

• Glycosidic bonds

Testosterone and estrogen are types of...

• Waxes
• Steroids
• Cholesterol
• Carbohydrates