Biochemistry Biology

In living cells, enzymes act as catalysts, which may reduce the amount of activation energy required for a chemical reaction to occur.  In the graphs below, pathway x is a solid line representing the uncatalyzed reaction. The dotted line shows the catalyzed reaction. Which graph best illustrates the changes in a reaction when the catalyst reduces the amount of energy required?

• A

• B

• C

• D

Answer explanation

Both lines begin at the same level but the catalyzed reaction shows a decrease in the activation energy...

Tags

NGSS.HS-PS1-4

The diagram shows the general structure of an amino acid. Which type of molecule is formed from amino acids?

• lipids

• proteins

• carbohydrates

• nucleic acids

Answer explanation

Amino Acids are the MONOMERS for building Proteins...

Tags

NGSS.HS-LS1-1

You are analyzing a compound in the laboratory. You find that it is made up of carbon, hydrogen, and oxygen in a ratio of two hydrogen atoms for each carbon atom. How will you classify the compound?

• lipid

• protein

• carbohydrate

• nucleic acid

Answer explanation

Although lipids are made of CHO only CARBOHYDRATES have the established distribution of elements of CHO in 121 arrangement...

Fats, oils and cholesterol are all types of what?

• cell membranes

• hormones

• lipids

• fatty acids

RNA and DNA are which type of macromolecules? 

• carbohydrate

• lipid

• nucleic acid

• protein

Answer explanation

Must remember: Nucleic Acids are the genetic information that is hereditary...

What will most likely happen if an appropriate enzyme is added to a chemical reaction? 

• The reaction rate will increase.

• The equilibrium of the reaction will be maintained. 

• The reaction rate will decrease.

• The reaction will stop.

Answer explanation

Enzymes speed up reactions by decreasing the activation energy...

Tags

NGSS.HS-PS1-5

A sugar, a phosphate group, and a nitrogen base form the building blocks of which organic compound?

• carbohydrates

• lipids

• nucleic acids

• proteins

The human body maintains a temperature of around 98.6 degrees at all times. Enzymes are involved in almost every chemical reaction in the body. Which of the following describes the connection between these two statements? 

• Enzymes function best at a specific temperature.

• The body needs to be warm to prevent hypothermia.

• The body is kept relatively warm to prevent too much enzyme action. 

• There is no connection between the two statements. 

Answer explanation

Extreme pH and temperature changes denature proteins damaging the active site of enzymes...

Tags

NGSS.HS-LS1-3

The enzyme lactase will break down the sugar lactose into which of the following components?

• monosaccharides

• nucleic acids

• amino acids

• phospholipids

Answer explanation

Lactose is a Disaccharide (two molecules of glucose bonded), the enzyme lactase breaks the lactose into two individual monosaccharides...

Water is essential for life. Its special properties make water the single most important molecule in plant life. Which of the following properties of water enables it to move from the roots to the leaves of plants?

• Water expands as it freezes.

• Water is an excellent solvent.

• Water exhibits cohesive behavior.

• Water is able to moderate temperature.