ATP-powered Pumps
ATP-powered pumps (ATPases) couple the splitting, or hydrolysis, of ATP with the movement of ions across a membrane against a concentration gradient. ATP is hydrolyzed directly to ADP and inorganic…
Difference between Cell Wall and Cell Membrane
One of the fundamental difference between the plasma membrane and the cell wall is in the type of organisms that they are found. The cell wall is present only in…
Cell Membranes
According to cell theory, cells are the main unit of organization in biology. Whether you are a single cell or a blue whale with trillions of cells, you are still made…
Cell Wall
Cell membranes surround every cell you will study. Cell walls made of cellulose are only found around plant cells and a few other organisms. Cellulose is a specialized sugar that is classified as a structural carbohydrate…
Permeases and Channels
Sisterhood of the Traveling Proteins Part II Experiment from last lecture reviewed. · It is possible to make a Heterokaryon cell with mouse and human cells. The human cell proteins can be visualized…
Active Transport
Active transport describes what happens when a cell uses energy to transport something. We're not talking about phagocytosis (cell eating) or pinocytosis (cell drinking) in this section. We're talking about the movement of individual molecules across the cell…
Passive Transport
While active transport requires energy and work, passive transport does not. There are several different types of this easy movement of molecules. It could be as simple as molecules moving freely such as osmosis or diffusion. You…
Desmosomes
Desmosomes Definition Desmosomes are a type of anchoring junction in animal tissues that connect adjacent cells. Anchoring junctions are button-like spots found all around cells that bind adjacent cells together.…
Centrioles – Organizing Chromosomes
Every animal-like cell has two small organelles called centrioles. They are there to help the cell when it comes time to divide. They are put to work in both the process…
Control of the Cell Cycle
The length of the cell cycle is highly variable, even within the cells of a single organism. In humans, the frequency of cell turnover ranges from a few hours in…
