In an animal cell, which two cell structures do newly-synthesised enzymes have to pass through to reach the external environment? write your answer in the form " "

Ribosomes, Cell membrane

Explanation:

Ribosomes can be described as structures which are involved in the production of proteins. Ribosomes are hence known to be the protein manufacturing units of a cell. As enzymes are also proteins,they will be synthesized in the ribosomes.

Cell membrane can be described as the membrane which is present outside the cell or which separates the cell from the external environment.

For an enzyme to pass through the external environment, it will have to pass through the ribosomes and the cell membrane.

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.