Chapter 5 Cell Membrane Model ⚛

phospholipid

structural unit of cell membranes composed of hydrophobic and hhydrophillic part

hydrophobic

the fear of water

hydrophilic

the love of water

cells

the basic fundamental unit of all living things

intracellular

inside the cell

extracellular

outside the cell

phospholipid

structural unit of cell membranes composed of hydrophobic and hydrophilic part

hydrophilic head

the circle part ofa phospholipid

Phospholipid bilayer is constructid of

2 layers of phospholipids, their heads pointing outwards and the tails touching each other

Cell membrane

protective and selective barrier created by a phospholipid bilayer

Which part of a phospholipid is hydrophobic?
The intracellular region
Phosphate group
The extracellular region
Fatty acid chain

Fatty acid chain

What is the fundamental unit of life?
Phospholipids
Water
Fatty Acids
Cells

Cells

How is the phospholipid bilayer oriented?
Heads face inward towards each other
One head layer touches the second tail layer
Head and tails alternate directions within a layer
One layer of phospholipids forms a circle
Tails face inward towards each other

Tails face inward towards each other

Which of the following is NOT true of the phosphate group in a phospholipid? The phosphate groups are...
attached to fatty acids via a glycerol group
positively charged
polar
hydrophilic
oriented in the bilayer so they interact with the water molecules on the inside and outside of the cell

positively charged

What language does the word 'hydro' come from?
Russian
Persian
Latin
Greek

Greek

cytoplasm

space within the cell containing all of its structures and components

Cell Membranes are

selectively permeable

Selectively Permeable

only allowing certain substances to pass through the cell membrane

Cell membranes are mostly composed of

phospholipid bilayer, cholesterol, proteins, carbohydrates

Fluid Mosaic model

different parts of the cell membrane float in a fluid like space

Cholesterol

molecule within hydrophobic space that helps maintain membrane fluidity

viscosity

resistance to fluid flow, of the phospholidpid bilayer

Fatty acids can be either____ or ______

saturated (having no double bonds) or unsaturated (having double bonds)

Saturated acids are usually________ in form

straight, rigid

Unsaturated acids are usually ______ in form

bent

Protein

there are two types integral and peripheral

Intigral proteins

membrane proteins that integrate into the phospholipid bilayer can even cross both sides to touch the inside and outside of the cell, to be able to do this they have hydrophobic domains that touch the hydrophobic reasons, and hydrophilic regions that touch the hydrophilic domains

Peripheral Proteins

membrane proteins on the outside of the phospholipids, on either side of the cell membrane

Membrane protein functions

structure
recognition sites
cell communication
transport

Carbohydrates

molecules attached to lipids or proteins that act as binding sites or help cells adhere to other cells

Which of the following is involved in cell communication?
Proteins
Cytoplasm
Phospholipids
Carbohydrates

Proteins

Carbohydrates in the cell membrane contribute to which of the following?
Structure
Cell to cell adhesion
Protection
Fluidity

Cell to cell adhesion

What is the purpose of cholesterol in the cell membrane?
To help maintain fluidity
To help cells stick together
To make the bilayer hydrophobic
To communicate with other cells

To help maintain fluidity

The Fluid Mosaic Model describes parts of the cell membrane such as proteins and phospholipids as _____.
bound to carbohydrates
tethered to one place in the membrane
as existing only on the cytoplasmic side of the cell
floating laterally throughout the space
as hydrophobic and hydrophilic molecules

floating laterally throughout the space

What is another term for the intracellular space?
Hydrophobic region
Phospholipids
Cytoplasm
Bilayer
Cholesterol

Cytoplasm

Concentration Gradient

A gradual difference in a solute concentration between two areas

Diffusion

movement from a high er concentration of solutes to a lower concentration of solute to equalize solute concentration

Passive Transport

Transport across the cell membrane that does not require energy

Simple Diffusion

Unassisted passage of small hydrophobic, nonpolar molecules from higher concentration to a lower concentration

Facilitated Firrusion

Passive transport that uses integral membrane proteins to help larger, charged, hydrophilic, and polar molecules across a concentration gradient

Carrier Proteins

Proteins that bind a molecule to facilitate transport through a cell membrane

Channel Proteins

Proteins that create a passageway to transport molecules and ions through the cell membrane

Osmosis

Passive transport of water across a membrane

Hypotonic Solution

less solutes, more water, like a hippo swimms in the water

Hypertonic Solution

More solutes less water

Isotonic

Equal concentration of solutes

Which types of molecules will easily pass through the fatty acid chains in the middle of the bilayer?
Polar
Ions
Hydrophilic
Hydrophobic

Hydrophobic

Diffusion of small, non-polar molecules across the cell membrane along a concentration gradient is...
Osmosis
Simple
Active
Channel
Facilitated

Simple

What type of transport uses membrane proteins to passively move solutes?
Osmosis
Facilitated diffusion
Simple diffusion
Active transport
All of these

Facilitated diffusion

The inside of a cell contains more solutes than the outside of the cell. Which describes the inside of the cell compared to the outside of the cell and what is the direction of water movement?
Inside the cell is hypertonic. Water will move toward the inside of the cell.
Inside the cell is hypertonic. Water will move toward the outside of the cell.
Inside the cell is hypotonic. Water will move toward the outside of the cell.
Isotonic. Water will not move in either direction.
Inside the cell is hypotonic. Water will move toward the inside of the cell.

Inside the cell is hypertonic. Water will move toward the inside of the cell.

Which type of integral membrane protein helps molecules move across the cell membrane by binding and releasing them?
Channel
Pore
Carrier
Hydrophilic
Hydrophobic

Carrier

Active Transport

transport against a concentration gradient that requires chemical energy

Uniport (uni one)

integral membrane protein that moves an ion or molecule in one direction

Antiport (anti against)

integral membrane protein that move two substances in opposite direction

Symport (sym same)

integral membrane protein that moves two substances in the same direction

Antiports and symports are

coupled transport, because they both transport two different substances to the same integral membrane protein

Why does active transport require energy?
To move solutes to an equal concentration inside and outside the cell
To move solutes against a concentration gradient
To diffuse substances passively
To transport small, hydrophobic molecules across the membrane
To move solutes with a concentration gradient

To move solutes against a concentration gradient

This type of integral membrane protein moves two substances in the same direction
Uniport
Triport
Antiport
Symport
Carrier
A sodium potassi

Symport

A sodium potassium pump is a type of...
Symport
Antiport
Uniport
Triport
Passive transport

Antiport

Chemical energy is required for active transport to establish a specific concentration gradient. In a sodium potassium-pump, chemical energy specifically serves to help the pump
Allow passive diffusion
Bind to the potassium ions
Create a symport
All of these
Change the shape

Change the shape

Active transport involves
Sodium ions
The movement of water
Simple diffusion
Movement with a concentration gradient
Chemical energy

Chemical energy

Endocytosis (endo = within)

import of molecules and particles into the cell wall by folding the cell membrane inwards

Vesicles

Circular buds comprised of membrane

Clathrin

a component of the protein that coats vesicles as they form from the plasma membrane

Phagocytosis (phago = devour)

the process where large molecules or other cells are eaten by engulfing them

Pinocytosis (pino = drink)

process where small, dissolved substances and liquids are taken up by a cell

Receptor-mediated endocytosis

a process that recognizes and targets a specific substrate through the help of integral membrane proteins on the cell membrane surface

Phagocytosis and Pinocytosis are ______ methods of endocytosis

non specific, they will consume any type

Repector mediated endocytosis is a _________ method of endocytosis

non specific

Caveolae (little caves)

pockets in the plasma membrane

Caveolins

membrane proteins that play a role in various metabolic pathways and cellular signaling

In mammals that are ____ different types of caveolins

3

Name the three different types of caveolins in mammals

caveolin 1, caveolin 2, caveolin 3

Lysosome

structure within the cell that contains digestive enzymes

Exocytosis

export of substances from the cell through a vesicle that fuses with the cell membrane (poop)

Exocytosis can be used to secrete newly made proteins out of the cell. It can also be used to add _____ directly to the cell membrane.
integral membrane proteins
solutes
lysosomes
protons

integral membrane proteins

A foreign cell has entered your blood stream. Which process describes how it can be engulfed by one of the cells in your immune system?
Pinocytosis
Phagocytosis
Exocytosis
Receptor-mediated cytosis
Lysosome

Phagocytosis

Which of these terms best describes the internalization of a specific protein from outside the cell?
Phagocytosis
Lysosome
Exocytosis
Pinocytosis
Receptor-mediated endocytosis

Receptor-mediated endocytosis

Which of these terms best describes the nonspecific internalization of dissolved substances outside the cell?
Pinocytosis
Lysosome
Phagocytosis
Exocytosis
Receptor-mediate endocytosis

Pinocytosis

Which of the following is true of the lysosome?
It builds internal cellular structures and proteins
It digests molecules from endocytosis
It maintains a basic pH
It pumps protons into the extracellular space

It digests molecules from endocytosis