AP Biology Tiffany Jones

According to the fluid mosaic model of cell membranes, phospholipids___________________.

• can shift laterally along the plane of the membranee

• frequently flip-flop from one side of the membrane to the other

• occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane

• have hydrophilic tails in the interior of the membrane

Which of the following types of molecules are hydrophilic and therefore excluded from the hydrophobic portion of the phospholipid bilayer?

• transmembrane proteins

• integral membrane proteins

• peripheral proteins

• cholesterol

Which of the following would likely diffuse through the lipid bilayer of a plasma membrane most rapidly?

• sucrose.

• an amino acid.

• O₂.

• Na⁺.

Which of the following processes is an "umbrella" term for the others?

• Osmosis.

• Facilitated diffusion.

• Passive transport.

• Transport of an ion down its electrochemical gradient.

Which of the following membrane activities requires energy from ATP?

• Facilitated diffusion of chloride ions through a chloride channel.

• Movement of Na⁺ ions from lower concentration in a mammalian cell to a higher concentration in the extracellular fluid.

• Movement of glucose molecules into a bacteria cell from a medium containing a higher concentration of glucose than inside the cell.

• Movement of carbon dioxide out of a paramecium.

An animal cell lacking in carbohydrates on the external surface of its plasma membrane would likely be impaired in which function?

• transporting ions against an electrochemical gradient

• cell-cell recognition

• attaching the plasma membrane to the cytoskeleton

• establishing a diffusion barrier to charged molecules

Which 4 elements make up most of all living matter?

• Carbon, Hydrogen, Nitrogen, Oxygen

• Carbon, Oxygen, Sodium, Potassium

• Carbon, Hydrogen, Calcium, Nitrogen

• Carbon, Oxygen, Nitrogen, Sulfur

A group of two or more atoms that are bonded together

• elements

• isotopes

• molecules

• essential elements of life

Tags

NGSS.HS-LS1-6

What is the difference between carbon-12 and carbon-14? (Hint: 12 and 14 are mass #)

• The number of protons in the nucleus.

• The number of protons and neutrons in the nucleus.

• The number of neutrons in the nucleus.

• The number of electrons in the orbitals.

Tags

NGSS.HS-PS1-8

When atoms share electrons unequally...

• nonpolar covalent bond is formed.

• ionic bond is formed.

• polar covalent bond is formed.

• hydrogen bond is formed.