A cell membrane is a thin layer that acts as a barrier that separates an individual cell or a cellular compartment from other surrounding structures. This dynamic layer plays an essential part in the transport of ions and nutrients.Know More
A cell membrane is a complex structure made of proteins, phospholipids, cholesterol, carbohydrates and several other compounds, all of which are held in place by non-covalent forces. Each cell membrane component serves one or more essential purposes. For example, the proteins act as pumps, gates or receptors, and the lipids create hydrophobic barriers that keep aqueous compartments separate. Cholesterol increases the strength and flexibility of the membrane while also making it less permeable to aqueous compounds.
The transport across cell membranes is an essential cell function, and it depends on the layered membrane structure and the nature of the molecule to be transported. Some molecules, such as oxygen and glucose, are transported through the membrane without requiring any energy, but ions, such as sodium and potassium, are only transported actively, which means that energy is required. The cell membrane is also capable of expelling part of its contents outside through a process called exocytosis or enveloping external molecules through endocytosis. Other functions of the cell membrane include providing shape to the cell by anchoring the cytoskeleton, maintaining the cell potential and sending molecular signals to other cells.Learn More
The final product of the Calvin cycle, the second metabolic cycle of photosynthesis, is the sugar glucose. Carbon dioxide joins with organic molecules to produce glyceraldehyde-3-phosphate. After several glyceraldehyde-3-phosphates are produced from the cycle, they join together to form glucose.Full Answer >
The mitochondria is the location inside the cell where the energy, called adenosine triphosphate, or ATP, is made. This specific part of the cell is composed of rod-shaped organelles. Mitochondria are the animal-version chloroplast, where the energy cycle in plants takes place.Full Answer >
If the cell membrane becomes totally impermeable, water and dissolved gases, most notably oxygen, would no longer be able to enter or leave the cell. The cell membrane is usually permeable to a number of substances, mostly small, nonpolar molecules. Other polar or charged particles are transported across the membrane by special embedded protein structures, and so would not be directly affected by a change in membrane permeability.Full Answer >
The process of meiosis results in four cells that possess half of the chromosomes of the original cell. This occurs in cells that possess two chromosome sets, which happens in organisms that reproduce sexually. The cellular biology of reproduction requires two gamete cells to interact.Full Answer >