The Cell Membrane

The Cell Membrane

The Cell Membrane:

• Controls what enters and leaves the cell

• Is present in all cells

• is also called the fluid mosaic model or plasma membrane

Multiple Select

What are the various names for the cell membrane?

• plasma membrane

• fluid mosaic model

• cell wall

• cell packaging

Multiple Select

What kind of cells have a cell membrane?

• virus

• bacteria

• plant

• animal

• eukaryotic

Multiple Choice

The function of the cell membrane is to:

• control what enters and leaves the nucleus

• control what enters and leaves the cell

• give a plant cell extra support

The Cell Membrane is made of:

• Phospholipids

• Proteins

• Carbohydrates

Multiple Choice

Which macromolecule is NOT found in the cell membrane?

• carbohydrates

• lipids

• proteins

• nucleic acids

Phospholipids:

• are a type of lipid (one of the four macromolecules)

• Have a polar, water-loving or hydrophilic head

• Have a non-polar, water-fearing or hydrophobic tail

• Form a bilayer when placed into water

Multiple Choice

What makes a phospholipid special?

• they are sugars

• they have a polar and a non-polar side

• they dissolve in water

Multiple Choice

Which side of a phospholipid interacts with water?

• the polar head

• the non-polar tail

Multiple Choice

What happens when phospholipids are added to water?

• they form a layer

• they turn upside down

• they form channels

• they form a bi-layer

The Proteins can be

• Integral: interact with the lipid bilayer

• Transmembrane: go all the way through the lipid bilayer

• Peripheral: Lie on top of the cell membrane

• 
  

Multiple Choice

Which type of protein goes all the way through the lipid bi-layer

• transmembrane

• peripheral

The proteins act as channels to let certain molecules into the cells

• Facilitated Transport- proteins do not need energy to help molecules into the cell

• Active Transport-proteins need energy to help molecules into the cell

• 
  

Multiple Choice

Which type of cell transport does NOT require energy?

• Active Transport

• Passive Transport

The carbohydrates:

• act as markers for other molecules and can recognize foreign invaders

• Glycoproteins- carbs attached to proteins

• Glycolipids- carbs attached to the phospholipid heads

Multiple Choice

What kind of molecule consists of a carbohydrate + a protein

• glycolipid

• glycoprotein

• cholestrol

• phospholipid

The cholesterol:

• is a part of the non-polar tails

• help to stabilize the cell membrane

• is type of lipid

Multiple Choice

The purpose of cholesterol is to:

• stabilize the cell membrane

• allow molecules to enter or leave the cell

• act as markers

The Cell Membrane is semipermeable

• Only small, non-polar molecules can come directly across the lipid bi-layer

• All other ions and molecules must use a protein channel because they are large and charged

• Water uses a "special" channel called an aquaporin

Multiple Choice

How does water enter the cell?

• aquaporins

• a door

• a window

• directly across the lipid bi-layer

Multiple Choice

Which kind of molecules can easily cross through the phospholipid bi-layer?

• small, charged particles

• large sugars

• small, non-polar molecules

• ions

• water