the plasma membrane key knowledge 1 aos 1 Flashcards
what is active transport?
active transport is the movement of molecules across a membrane from a region of lower concentration to a region of higher concentration—against the concentration gradient. Active transport requires cellular energy to achieve this movement
what are aquaporins?
Aquaporins are integral membrane proteins from a larger family of major intrinsic proteins that form pores in the membrane of biological cells, mainly facilitating transport of water between cells
what is a carrier protein?
The carrier proteins facilitate diffusion of molecules across the cell membrane. The protein is imbedded in the cell membrane and covers the entire membrane. This is important because the carrier must transport the molecule in and out of the cell.
what is the plasma membrane?
The plasma membrane, also called the cell membrane, is the membrane found in all cells that separates the interior of the cell from the outside environment. … The plasma membrane consists of a lipid bilayer that is semipermeable. The plasma membrane regulates the transport of materials entering and exiting the cell.
what are cell surface markers?
Cell surface markers are special proteins and carbohydrates attached to the cell membrane. cell surface markers play a role in inter-cellular communication and recognition.
what is a channel protein?
A channel protein is a special arrangement of amino acids which embeds in the cell membrane, providing a hydrophilic passageway for water and small, polar ions. Like all transport proteins, each channel protein has a size and shape which excludes all but the most specific molecules.
what is endocytosis?
Endocytosis is the process of actively transporting molecules into the cell by engulfing it with its membrane.
what is endoplasmic reticulum?
The smooth endoplasmic reticulum (smooth ER) is a membranous organelle (often made of cisternae) found in most eukaryotic cells.
main functions;
- the synthesis of lipids and steroid hormones
- the detoxification of harmful metabolic byproduct
-the storage and metabolism of calcium ions within the cell.
what is a eukaryotic cell?
Eukaryotic cells are cells that contain a nucleus and organelles, and are enclosed by a plasma membrane
what is exocytosis?
a process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane.
what is facilitated diffusion?
Facilitated diffusion is the passive movement of molecules across the cell membrane via the aid of a membrane protein
It is utilised by molecules that are unable to freely cross the phospholipid bilayer.
This process is mediated by two distinct types of transport proteins – channel proteins and carrier proteins
what is the fluid mosaic model?
Fluid – the phospholipid bilayer is viscous and individual phospholipids can move position
Mosaic – the phospholipid bilayer is embedded with proteins, resulting in a mosaic of components
what is a glycoprotein?
- proteins with a sugar attached to them
- Glycoproteins are always found on the outside of the plasma membrane, with the sugar facing out.
functions;
-in the immune system (such as antibodies)
-protecting the body
-communication between cells
-reproductive systems.
what is the golgi complex?
The Golgi complex is a cell organelle and is made of a stack of small flat sacs formed by membranes inside the cell’s cytoplasm. A major function is the modifying, sorting and packaging of proteins for secretion. It is also involved in the transport of lipids around the cell, and the creation of lysosomes.
what does it mean to be hydrophilic?
A hydrophilic molecule or portion of a molecule is one whose interactions with water and other polar substances are more favorable than their interactions with oil or other hydrophobic solvents. They are typically charge-polarized and capable of hydrogen bonding
