Biochemistry, pH, and Water_A

Which of these solutions is the strongest acid?

• Dish Soap: pH of 12

• Tomato Soup: pH of 4

• Baking Soda: pH of 9

• Drain Cleaner: pH of 14

What property of water helps to moderate earth's temperature?

• adhesion
• chohesion
• Specific heat capacity
• Latent heat of vaporization

Which is least likely a primary function of proteins?

• to act as an organic catalyst
• to supply short term energy
• to build and repair damaged cells
• to defend against foreign invaders

Which of the following is NOT TRUE about enzymes?

• they are proteins

• they can change shape when temperature or pH changes

• they are consumed or used up in chemical reactions

• they speed up the rate of chemical reactions

Why does water move from the roots to the leaves of plants?

• Water is pushed by solutes
• Capillary action pulls the water molecules like a chain
• Water is pulled by gravity
• Water’s cohesion causes it to “pull” towards the leaves

Which organic compounds necessary for life are formed by a sugar bonded to a phosphate group and a nitrogenous base?

• lipids
• proteins
• nucleic acids
• carbohydrates

Tags

NGSS.HS-LS1-6

Which of the following is LEAST likely to dissolve in water?

• nonpolar fats and oils
• polar sugar molecules
• salt made of a positive sodium ion and a negative chloride ion
• all of the substances will dissolve easily in water

Tags

NGSS.HS-PS1-3

Which of these statements shows a monomer creating the correct macromolecules?

• amino acids combine to make proteins

• glucose molecules combine to make nucleic acids

• nucleic acids combine to make starch

• proteins combine to make glucose

The elements found in nucleic acids but not carbohydrates and lipids are __________________________.

• nitrogen and sulfur
• nitrogen and phosphorus
• carbon and hydrogen
• iron

 Small insects can walk across the surface of calm water. Their feet push the surface of the water down slightly, somewhat like a person walking across a trampoline, but they do not break the surface. What is the best explanation for why this happens?

• The insects are light enough so that they do not break the hydrogen bonds holding the water molecules together
• The insects actually use their wings to hover slightly above the water's surface and they only skim it with their feet
• The insects' feet are non-polar, so they are repelled by the polar water molecules and are pushed away from the water's surface
• The insects are small enough to see the individual water molecules, so they are able to step carefully from one molecule to the next

Tags

NGSS.MS-PS2-5