Biology Active Transport, Endocytosis, and Exocytosis Sec 3.5
Active transport proteins and enzymes are similar because they are both proteins that recognize only specific target molecules and change it shape when they bind.
In what ways are active transport proteins similar to enzymes?
Active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. Cells use active transport to get needed molecules regardless of the concentration gradient and to maintain homeostasis. All of transport proteins span the membrane, and most change shape when they bind to a target molecule or molecules. Some transport proteins bind to only one type of molecule. Others bind to two different types. Some proteins that bind to two types of molecules move both types in the same direction. Other molecules move in opposite directions. The key feature of active transport proteins is that they can use chemical energy to move a substance against its concentration gradient. Most use energy from a molecule called ATP. The sodium potassium pump uses energy directly from the breakdown of ATP. It palms three sodium ions out of the cell for every two potassium ions pumps in. The proton pump, another transport protein, uses energy from the breakdown of ATP to move hydrogen ions or protons out of the cell. This action forms a concentration gradient of hydrogen ions (H+), which makes the fluid outside the cell more positively charged in the fluid inside.
What is active transport?
Endocytosis is responsible for releasing neuron transmitters which pass electrical impulses along from neuron to neuron.
What is endocytosis responsible for?
Endocytosis is the process of taking liquids or fairly large molecules into a cell by engulfing them in the membrane. In the process the cell membrane makes a pocket around a substance. The pocket breaks off inside the cell and forms a vesicle, which then fuses with a lysosome or a similar type of vesicle.
What is endocytosis?
Exocytosis is the opposite of endocytosis it is the release of substances out of a cell by the fusion of a vesicle with the membrane. During this process, a vesicle forms a round materials to be sent out of the cell. The vesicle then moves toward the cells surface, where it fuses with the membrane and let's go of its content.
What is exocytosis?
Phagocytosis is a type of endocytosis in which the cell membrane and engulfs large particles. Phagocytosis plays a key role in your immune system. Some white blood cells called macrophages help your body fight infection. They find foreign materials, such as bacteria, and engulf and destroy them.
What is phagocytosis?