Describe importance of proteins, carbohydrates and lipids as components of plasma membrane

Plasma membrane is made up of a phospholipid bilayer. To be more exact  there is two fatty acids making up the polar hydrophilic head, and a phosphate group attached as the non-polar hydrophobic tail. Proteins have many uses in regards to the cell membrane. In a nutshell they are used for diffusion of molecules across the plasma membrane. They are different types of diffusion, most noteably you should try and know the different between passive and active transport the latter of which involves a protien pump. Carbohydrates are used for cushiing the cell membrane and for cell recognition.

Explanation: I learned this in class, I'm in IB Bio HL

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.