Transport Mechanisms in Cells: How Cells Control What Enters and Leaves - Q2

It is more than just a barrier; it's a dynamic, intricate structure that acts as the cell's gatekeeper, regulating everything that enters and exits.

cell membrane

It's primarily composed of a phospholipid bilayer, a double layer of lipid molecules.

cell membrane

This consists of phospholipids that has a hydrophilic

(water-loving) head and two hydrophobic

(water-fearing) tails.

Phospholipid Bilayer

These molecules naturally

arrange themselves into a _______, with the heads

facing the watery environments inside and

outside the cell, and the tails tucked safely in the

middle.

Phospholipid Bilayer

This unique structure (from the bilayer) gives the cell membrane its ____________?

Selective Permeability

The unique structure of the cell membrane give it its

_____________, meaning it allows certain

substances to pass through while blocking

others. It's like a bouncer at an exclusive club,

only letting in the right guests.

Selective Permeability

Scattered throughout the bilayer are various

proteins. These are known as?

Embedded Proteins

These proteins are crucial for

transport, acting as channels or carriers that

facilitate the movement of specific molecules that

cannot pass directly through the lipid bilayer.

Embedded Proteins

It can be broadly categorized into two main types: Passive Transport and Active Transport. The key difference between them lies in whether they require the cell to expend energy.

Cellular Transport mechanisms

The key difference between them lies in whether they require the cell to expend energy.

Passive Transport and Active Transport.

Movement of molecules

without cellular energy,

down their concentration

gradient (from high to low

concentration).

Passive Transport

Movement of molecules

against their concentration

gradient (from low to high

concentration), requiring

cellular energy in the form of

ATP.

Active Transport

Diffusion, Osmosis,

Facilitated Diffusion are examples of?

Passive Transport

Sodium-Potassium Pump,

Glucose Reabsorption in

Kidneys are examples of?

Active Transport

It is like rolling a ball downhill; it happens naturally without requiring extra effort from the cell.

Passive transport

Molecules move

from an area of higher concentration to an area of lower concentration, driven by the random motion of particles.

Passive transport

The simplest form of passive

transport, where small, uncharged

molecules like oxygen and carbon

dioxide move directly across the lipid

bilayer from a region of high

concentration to low concentration

until equilibrium is reached.

Diffusion

This is the special case of water

diffusion across a selectively

permeable membrane.

Osmosis

Water moves

to equalize solute concentrations,

always moving from an area of higher

water concentration (lower solute) to

lower water concentration (higher

solute).

Osmosis

Larger or charged molecules, such as

glucose or ions, cannot easily pass

through the lipid bilayer. Therefore they need to do?

Facilitated Diffusion

They (larger or charged molecules) rely on

specific transport proteins (channel

proteins or carrier proteins) embedded

in the membrane to "facilitate" their

movement down the concentration

gradient. Which type of passive transport is this?

Facilitated Diffusion

Unlike passive transport, this type of transport requires the cell to expend energy, usually in the form of Adenosine Triphosphate (ATP), to move molecules.

Active Transport

This process is essential for transporting substances against their concentration gradient, from an area of lower concentration to an area of higher concentration.

Active Transport

This type of transport directly uses ATP to power

protein pumps that move specific ions or molecules

across the membrane.

Primary Active Transport

Primary Active Transport

A classic example of this transport is the

Sodium-Potassium pump, which maintains the

electrochemical gradient crucial for nerve impulses

and muscle contractions.

Also known as co-transport, this mechanism (type of active transport) doesn't directly use ATP.

Secondary Active Transport

Instead, it harnesses the energy

stored in an existing electrochemical gradient (often

created by primary active transport) to move another

molecule against its own gradient.

Secondary Active Transport

For instance, the

movement of sodium ions down their gradient can

power the uptake of glucose into cells. What type of transport is this?

Secondary Active Transport

The principles of cell transport aren't just abstract biological concepts; they have profound implications in everyday life and ______.

medicine

When patients receive _______, they must be

isotonic to prevent damage to red blood

cells.

Intravenous (IV) Fluids

These fluids should be Isotonic (solutions have the same solute

concentration as blood plasma), ensuring no

net movement of water into or out of the cells,

thus preventing them from bursting or

shriveling. What example does this fall into?

Intravenous (IV) Fluids

__________ have the same solute

concentration as blood plasma, ensuring no

net movement of water into or out of the cells,

thus preventing them from bursting or

shriveling.

Isotonic solutions

Intravenous (IV) Fluids, Kidney Function, Plant Water Absorption are examples of?

Cell Transport in Real Life

Our _______ are vital for filtering blood.

Kidney Function

______

cells actively reabsorb essential substances

like glucose, salts, and amino acids from

the filtrate back into the bloodstream.

Kidney

This real life example of

active transport ensures that valuable

nutrients are not lost in urine, maintaining the

body's balance.

Kidney Function

Plants absorb water from the soil primarily

through osmosis. What real life example of Cell transport is this?

Plant Water Absorption

Root cells have a higher

concentration of solutes than the surrounding

soil water, creating a water potential gradient

that drives water into the roots. This is an example of?

Plant Water Absorption

This passive

process is crucial for plant hydration and

survival.

Plant Water Absorption

In Plant Water Absorption,

Plants absorb water from the soil primarily

through what?

osmosis

Kidney Function

Our kidneys are vital for filtering blood. Kidney

cells actively reabsorb essential substances

like ____________ from

the filtrate back into the bloodstream.

glucose, salts, and amino acids

Secondary active transport is also known as _________ because it doesn’t directly use ATP.

Co-transport

In Plant water absorption,

Root cells have a higher

concentration of solutes than the surrounding

soil water. why does this drive water into the roots.

Due to a water potential gradient