Living Environment Unit One - Explaining commonly missed concept

Which substances play an important role in communication between cells in multicellular organisms by acting as chemical messengers?

• hormones

• fats

• minerals

• antibiotics

The shape of a protein is most directly determined by the

• amount of energy available for the synthesis of the protein

• kind and sequence of amino acids in the protein

• type and number of DNA molecules in a cell

• mistakes made when the DNA is copied

Which statement best describes enzymes?

• They slow down the rate of breathing

• They are the building blocks of polymers

• They speed up the conduction of impulses along a nerve cell

• They influence the rate of chemical reactions

What happens to an enzyme when it is denatured?

• It becomes stronger

• Activation energy lowered

• Activation energy is raised

• It loses its shape

What is a substrate?

• The product that an enzyme acts on when it catalyzes a chemical reaction

• both answers

• None

• The reactant that an enzyme acts on when it catalyzes a chemical reaction

One side of the water molecule has a positive charge, while the other side has a negative charge. What does the charge tell you about the water molecule?

• Water is a polar molecule

• Water is a nonpolar molecule

• Water has an overall positive charge

• Water has an overall negative charge

Which term refers to all the chemical activities that occur in an organism?

• synthesis

• transport

• metabolism

• nutrition

Identify the building blocks created when an enzyme breaks down starches (another word for plant carbohydrates) during digestion

• amino acid

• glucose

• nucleic acid

• polypeptide

Match the following macromolecule to the monomers produced from digestion

• Fatty Acids

• Lipids

• Glucose

• Protein

• Amino Acid

• Carbohydrates

Reorder the following. What steps must occur for your body to return to homeostasis after eating a carby meal?

• glucose in blood is converted into glycogen and stored in the muscles

• Your digestive system uses enzymes to break down the starch into glucose that is absorbed into the blood

• You eat a carbohydrate such as bread or rice

• Insulin is released to reduce blood sugar levels

• homeostasis is restored