Hypotonic refers to the solution with the lower concentration of solutes when two solutions are compared. The water will diffuse out of the hypotonic solution and into the hypertonic solution.
Hypertonic refers to the solution with the higher concentration of solutes when two solutions are compared. The water will flow into the hypertonic solution from a hypotonic solution.
When two solutions are compared, both solutions have an equal concentration of solutes. Therefore, there will be no net flow of water into or out of the cell.
Molecules bind to specific receptor proteins embedded in a coated pit within the plasma membrane. When enough particles accumulate in the pit, it deepens, seals, and is engulfed into the cell as a vesicle.
Pinocytosis is a type of endocytosis that occurs when vesicles form around a fluid and is ingested into the cell.
When the material taken in is large, such as bacteria or food particles, the plasma membrane surrounds the particle and engulfs it.
A form of bulk transport that is the reverse process of exocytosis. The membrane bound vesicles move to the surface of the plasma membrane, fuse with the membrane and then release the contents within the vesicle to the outside of the cell.
A form of bulk transport in which the cell's plasma membrane surrounds and engulfs the particle. The particle is engulfed in a vesicle and transported into the cell.
Integral membrane protein involved in the secondary active transport of two different molecules in opposite direction.
Integral membrane protein that is involved in the secondary active transport of two different molecules in the same direction through the cell membrane. The transporter proteins involved in this process is the cotransporters.
The sodium-potassium pump can be found in the cell membrane (of animal cells) and is a type of primary transport. For every ATP consumed, the enzyme pumps 3 sodium ions out of the cell and 2 potassium inside of the cell.
The energy used in active transport comes from ATP, which is a chemical compound. It is composed of three phosphate groups. When one of the groups is removed by the breaking of the phosphoanhydride bond, a form of covalent bond, large amounts of energy is released. This energy can be harnessed for cellular work.
Bulk transport is a type of active transport as it requires energy. This type of transport allows the movement (into or out of a cell) of molecules that are too large to be moved by transport proteins.
In this type of active transport there is no direct coupling of ATP. It is powered by the potential energy that comes from the electrochemical potential difference.
Involves the direct use of metabolic energy (ATP Hydrolysis) for the transport of particles in and out of the cell. This creates an electrochemical gradient.
By allowing the cell to move substances in and out of the cell, both of these types of transports allows the cell to maintain an internal balance (equilibrium).
The purpose of both these types of transports is to move material across the cell membrane
Energy is required for active transport because the molecules against the concentration gradient (Low concentration to high concentration).
A symporter is a cotransporter and integral membrane protein.
An antiporter is a cotransporter and integral membrane protein.
Energy is not required for any passive transport because the movement of the materials goes along with the concentration gradient (High concentration to low concentration).
The secondary transport uses the potential energy from the concentration gradient that was created by the primary transport.

CELL MEMBRANE TRANSPORT

Passive Transport
The movement of substances
into or out of a cell without
the expenditure of energy.

Active Transport
The movement of substances
into or out of a cell with
the use of cellular energy.

Primary Transport

Substances carried in the primary transport are Na+, K+, Mg2+, and Ca2+.

Sodium-Potassium Pump

How does the Pump Operate?
The sodium-potassium pump is driven by the Na⁺/K⁺-ATPase enzyme. The pump uses energy from ATP to transport substrates (sodium and potassium) across the cell membrane.

The three Na⁺ ions, located inside of the cell, binds to the active site of the transport protein (ATPase). As the substrate binds to the enzyme's active site, the enzyme-substrate complex is formed. Meanwhile, the ATP binds to the enzyme's allosteric site causing for a change in the shape of the protein. This allows for a ionic transport across the membrane. The change in shape of the carrier protein allows the release of the Na⁺ ions to the outside of the cell. This exposes new active sites for the K⁺ ions. The K⁺ binds to the new active sites of the enzyme, forming another enzyme-substrate complex. When a new ATP binds to the enzyme's allosteric site, the K⁺ ions are released into the cell. This once again exposes the active sites for Na⁺, allowing the cycle to start again.

Na⁺/K⁺-ATPase enzyme plays a huge role in maintaining various cellular functions in the human body. If the enzyme is met with inhibition, there can be devastating pathological effects that can cause many problems. This is because inhibition can cause high intracellular Na⁺ ion levels and an increase in Ca2+through the Na⁺/Ca2+exchanger.

Secondary Transport

Symporter

Antiporter

Bulk Transport

Endocytosis

Phagocytosis

Pinocytosis

Receptor-Mediated
Endocytosis

Exocytosis

Endocytosis is often used to get rid of waster made by the cells. It is also employed to transport vital material produced by cells outside of the cells.

Adenosine triphosphate (ATP)

Structure of the Cell Membrane
Composed primarily of three things

Phospholipids

Phospholipids have two parts: a head and two tails. The head is composed of phosphate molecules that are hydrophilic. The two tails are composed of fatty acid chains that are hydrophobic. Cells have a phospholipid bilayer: two layer of phospholipids.

The hydrophilic regions of the phospholipids form hydrogen bonds and ionic bonds with its aqueous environment. Other, weaker forces stabilize the bilayer of the cell membrane.

Proteins

Integral and peripheral proteins can be found on the surface of the phospholipid bilayer. Integral proteins aid in transporting different molecules across the cell membrane. They can be found sticking out on either end. Peripheral proteins do not extend across the membrane. They help with transport or communication.

Cholesterol

Cell membrane also contains cholesterol that is randomly distributed across the phospholipid bilayer. Cholesterol helps the bilayer remain fluid in different environmental conditions.

Concentration Gradient

Aquaporin

Tonicity

Isotonic

Hypertonic

Hypotonic

Cotransporter