V Figure 17.24 Coupled transcription and translation in bacteria. In bacterial cells, the translation of MRNA can begin as soon as the leading (5') end of the mRNA molecule peels away from the DNA template. The micrograph (TEM) shows a strand of E. coli DNA being transcribed by RNA polymerase molecules. Attached to each RNA polymerase molecule is a growing strand of mRNA, which is already being translated by ribosomes. The newly synthesized polypeptides are not visible in the micrograph but are shown in the diagram. RNA polymerase DNA MRNA Polyribosome 0.25 p Direction of transcription RNA polymerase, DNA Polyribosome- Polypeptide (amino end) Ribosome MRNA (5' end)- VISUAL SKILLS > Which one of the MRNA molecules started being transcribed first? On that MRNA, which ribosome started translating the MRNA first?
Structure and Composition of Cell Membrane
Despite differences in structure and function, all living cells in multicellular organisms are surrounded by a cell membrane. Just like the outer layer of the skin separates the body from its environment similarly, the cell membrane, also known as 'plasma membrane,' separates the inner content from its exterior environment.
Cell Membrane
The cell membrane is known by different names like plasma membrane or cytoplasmic membrane, or biological membrane. The term "cell membrane" was first introduced by C. Nageli and C. Cramer in the year 1855. Later on, in 1931, the term "plasmalemma" for cell membrane was given by J. Plowe. The cell membrane separates the cell's internal environment from the extracellular space. This separation allows the protection of cells from their environment.
Prokaryotes vs Eukaryotes
The cell is defined as the basic structural and functional unit of life. The cell membrane bounds it. It is capable of independent existence.
Would the coupling of the processes shown in Figure 17.24 be found in a eukaryotic cell? Explain why or why not.
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
