Active transport review

What is a vesicle?

A small, membrane bound compartment that allows molecules to be transported through the cell

Compare and contrast passive vs active transport

Both types of transports allow materials into and out of the cell, in order for the cell to complete its function. Some types of transports use proteins to assist with moving items across the membrane. Passive transport- does NOT require energy and goes with the gradient (high to low) -types diffusion, facilitated diffusion, osmosis Active transport- requires energy, can move against the gradient, (low to high), moves larger molecules, bulk. ex. sodium potassium pump, endocytosis, exocytosis

active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference- low concentration to a high concentration

How does bulk transport across the plasma membrane occur?

Movement of Large Compounds Requires energy Type of Active transport that does not always move from low concentration to high concentration

Describe phagocytosis

Phagocytosis begins when the particle binds to a plasma membrane receptor. Pseudopods surround the particle outside the cell, and the membranes fuse to form a vesicle called a phagosome which enters the cytoplasm. The phagosome fuses with one or more lysosomes, and the lysosomal enzymes break down the ingested material.

Describe the sodium potassium pump

- An active transport mechanism - uses 3 NA+ (sodium) out of the cell and 2 K+ (potassium) into the cell. - ATP used to change the shape of the carrier protein remember 3,2,1 three sodium (NA) out 2 potassium (K) in 1 ATP molecule required

How would you identify active transport?

1) you see an atp molecule 2) molecules are going from low to high concentration 3) vesicles are moving molecules across the membrane

Describe endocytosis

endocytosis is when the cell membrane engulfs a particle and brings it into the cell, forming a vesicle

Describe exocytosis

exocytosis is when particles are expelled, usually from the Golgi apparatus forming vesicles and having it fuse with the surface of the cell

What are the two types of endocytosis?

pinocytosis and phagocytosis

Which macromolecules are in the plasma membrane? What is their functions?

proteins- creates a channel for molecules to move through cholesterol- keeps the cell flexible by helping the tails not to stick together, without cells would be rigid phospholipids- make up the bulk of the plasma membrane allow for endocytosis and exocytosis carbohydrates help to recognize molecules

passive transport

the movement of substances across a cell membrane without the use of energy by the cell. Molecules move down a concentration gradient from high to low.

Name the types of active transport

The Sodium-Potassium pump, Exocytosis, and Endocytosis.