LE Regents Review: Cell Transport & Biochemistry

Which statement explains the importance of maintaining a constant internal environment to ensure proper enzyme functioning?

•  Changes in pH and temperature will cause the enzyme reaction rate to be too fast.
• Temperature and pH determine amino acid sequences in enzymes
• Changes in pH will change the genetic instructions of enzymes
• Increasing the temperature and pH can alter the specific shape of enzymes.

Hospital patients are often given intravenous fluids (IVs) to maintain proper levels of water and salts in the body. Great care is used in preparing these solutions. If a manufacturer accidentally prepared a batch of IV fluid that contained much more than the usual amount of salt, harm to the patient could result. The most likely effect on a patient if this incorrectly prepared IV fluid was used is that

• water would move into body cells and cause them to burst
•  water would move out of body cells and cause them to dehydrate
•  salt and water would both move out of body cells and disrupt homeostasis
• salt and water would both move into body cells and preserve homeostasis

Tags

NGSS.HS-LS1-3

Which substance is an organic molecule?

• water
• oxygen
• sugar
• carbon dioxide

Tags

NGSS.HS-LS1-6

Which substance is an inorganic molecule?

• water
• starch
• DNA
• fat

The graph activity of which enzyme decreases in both acidic and basic environments? 

• chymotrypsin
• cholinesterase
• pepsin
• papain

Cell membranes are said to be selectively permeable. Which statement best explains what selectively permeable means?

• The cell membrane prevents any harmful substance from entering the cell.
• The cell membrane lets certain substances enter the cell and keeps certain substances out of the cell.
• The cell membrane allows only large molecules to diffuse into the cell.
• The cell membrane has pores that let only water and glucose into the cell and carbon dioxide out.

Tags

NGSS.MS-LS1-2

Base your answer to the question on the diagram below and on your knowledge of biology. The diagram represents two solutions, A and B, separated by a selectively permeable membrane. Which statement best describes the outcome after 20 minutes?

• Solution A will contain approximately the same number of glucose molecules as solution B.
• Solution A will contain all of the water molecules.
• Solution B will remain unchanged.
• Solution B will lose all of the glucose molecules to solution A.

The diagram below represents a cell in water.  Formulas of molecules that can move freely across the cell membrane are shown.  Some molecules are located inside the cell and others are in the water outside the cell.

Based on the distribution of these molecules, what would most likely happen after a period of time?

• The concentration of O₂ will increase inside the cell.
• The concentration of CO₂ will remain the same inside the cell.
• The concentration of O₂ will remain the same outside the cell.
• The concentration of CO₂ will decrease outside the cell.

Tags

NGSS.HS-LS1-7

NGSS.HS-LS2-3

A substance is most likely to diffuse into a cell when

• it is a large organic food molecule such as protein or starch
• it is enclosed in an organelle such as a vacuole
• the concentration of the substance is greater outside the cell than inside
• the pH of the substance is greater than the pH of the cellListen

Tags

NGSS.MS-LS1-2

The diagram below shows the relative concentration of molecules inside and outside of a cell.

Which statement best describes the general direction of diffusion across the membrane of this cell?

• Glucose would diffuse into the cell.
• Protein would diffuse out of the cell.
• Oxygen would diffuse into the cell.
• Carbon dioxide would diffuse out of the cell.

Tags

NGSS.MS-LS1-2