Diffusion, Osmosis, Active Transport

Only available on StudyMode
  • Download(s) : 73
  • Published : February 16, 2013
Open Document
Text Preview
Lipids and Phospholipids

The main role of phospholipids is that they can form lipid bilayers. It is an amphipathic molecule. The head which is hydrophilic contains a group of phosphate, a diglyceride and a simple molecule e.g. choline. The tail is hydrophobic and is made up of fatty acids. Phospholipids receive and transmit signals across the cell membrane and act as a store room for energy. The main role of phospholipids is that they can form lipid bilayers. It is an amphipathic molecule. The head which is hydrophilic contains a group of phosphate, a diglyceride and a simple molecule e.g. choline. The tail is hydrophobic and is made up of fatty acids. Phospholipids receive and transmit signals across the cell membrane and act as a store room for energy. Fatty acids

Fatty acids
Glycerol
Glycerol
Phosphate
Phosphate
Choline
Choline

Cholesterol
Cholesterol

Hydroxyl head – is hydrophilic and therefor orients itself with the polar heads of the phospholipids. Hydroxyl head – is hydrophilic and therefor orients itself with the polar heads of the phospholipids. Steroid Rings – Consists of four hydrogen rings which attract the tail of the phospholipid to make the cell membrane less soluble Steroid Rings – Consists of four hydrogen rings which attract the tail of the phospholipid to make the cell membrane less soluble

Cholesterol can approximately make up 50% of the plasma membrane. It Reduces membrane fluidity by reducing phospholipid movement therefor giving the membrane the shape it needs instead of it looking like a deflated balloon. It also maintains its flexibility over a range of temperatures for example it prevents solidification at low temperatures. Cholesterol can approximately make up 50% of the plasma membrane. It Reduces membrane fluidity by reducing phospholipid movement therefor giving the membrane the shape it needs instead of it looking like a deflated balloon. It also maintains its flexibility over a range of temperatures for example it prevents solidification at low temperatures.

The role of biological molecules in the structure of the plasma membrane and in transport of molecules across the cell membrane. The role of biological molecules in the structure of the plasma membrane and in transport of molecules across the cell membrane.

Proteins
Proteins

The primary structure is a sequence of amino acids held together by peptide bonds. This is known as a polypeptide chain.The sequence of the amino acids instructs the function of the protein. The sequence of the amino acids is dependent on the genetic DNA. The primary structure is a sequence of amino acids held together by peptide bonds. This is known as a polypeptide chain.The sequence of the amino acids instructs the function of the protein. The sequence of the amino acids is dependent on the genetic DNA. Proteins are polymers of amino acids. Amino acids can contain elements of carbon, hydrogen, oxygen, nitrogen and sulphur. The combined shape of the secondary and tertiary structure and the quaternary structure is referred to as the conformation of the protein. Proteins are polymers of amino acids. Amino acids can contain elements of carbon, hydrogen, oxygen, nitrogen and sulphur. The combined shape of the secondary and tertiary structure and the quaternary structure is referred to as the conformation of the protein. A secondary structure folds up on itself and twists around to create a 3 dimensional shape this is known at the tertiary structure. The tertiary structure of a protein is held together by the bonds formed by the side groups, and there is quite a variety of different bonds that can cause the tertiary structure to form. A secondary structure folds up on itself and twists around to create a 3 dimensional shape this is known at the tertiary structure. The tertiary structure of a protein is held together by the bonds formed by the side groups, and there is quite a variety of different bonds that can cause the tertiary...
tracking img