Notes on Cells under the Microscope
Unit II Test Review
Chapter 4
BB Notes
Cells Under the Microscope
Cells are microscopic in size. Although a light microscope allows you to see cells, it cannot make out the detail that an electron microscope can.
The overall size of a cell is regulated by the surface-area-to-volume ratio.
4.2 The Plasma Membrane
The plasma membrane of both prokaryotes and eukaryotes is a phospholipid bilayer.
The phospholipid bilayer regulates the passage of molecules and ions into and out of the cell.
The fluid-mosaic model of membrane structure shows that the embedded proteins form a mosaic (varying) pattern.
The types of embedded proteins are channel, transport, cell recognition, receptor, and enzymatic proteins.
4.3 The Two Main Types of Cells
The cell theory states that all life is made of cells.
Some of the differences between prokaryotic cells and eukaryotic cells are presented in Table 4.1
All cells have a plasma membrane, a cytoplasm, and genetic material.
Prokaryotic cells lack a nucleus but possess a nucleoid region where the genetic material is located. Prokaryotic cells are surrounded by a cell wall and capsule, and they often move with the use of a flagella. The cytoplasm contains ribosomes for protein synthesis.
4.4 Eukaryotic Cells
Eukaryotic cells, which are much larger than prokaryotic cells, contain organelles, compartments that contain enzymes for specialized functions. A summary of these organelles and other structures is provided in Table 4.2.
Nucleus and Ribosomes
The nucleus houses chromatin, which contains DNA, the genetic material. During division, chromatin becomes condensed into chromosomes.
The nucleolus is an area within the nucleus where ribosomal RNA is produced. Proteins are combined with the rRNA to form the subunits of ribosomes, which exit the nuclear envelope throughnuclear pores.
Ribosomes in the cytoplasm synthesize polypeptides using information transferred to the DNA by mRNA.
Endomembrane System
The endoplasmic
Chapter 4
BB Notes
Cells Under the Microscope
Cells are microscopic in size. Although a light microscope allows you to see cells, it cannot make out the detail that an electron microscope can.
The overall size of a cell is regulated by the surface-area-to-volume ratio.
4.2 The Plasma Membrane
The plasma membrane of both prokaryotes and eukaryotes is a phospholipid bilayer.
The phospholipid bilayer regulates the passage of molecules and ions into and out of the cell.
The fluid-mosaic model of membrane structure shows that the embedded proteins form a mosaic (varying) pattern.
The types of embedded proteins are channel, transport, cell recognition, receptor, and enzymatic proteins.
4.3 The Two Main Types of Cells
The cell theory states that all life is made of cells.
Some of the differences between prokaryotic cells and eukaryotic cells are presented in Table 4.1
All cells have a plasma membrane, a cytoplasm, and genetic material.
Prokaryotic cells lack a nucleus but possess a nucleoid region where the genetic material is located. Prokaryotic cells are surrounded by a cell wall and capsule, and they often move with the use of a flagella. The cytoplasm contains ribosomes for protein synthesis.
4.4 Eukaryotic Cells
Eukaryotic cells, which are much larger than prokaryotic cells, contain organelles, compartments that contain enzymes for specialized functions. A summary of these organelles and other structures is provided in Table 4.2.
Nucleus and Ribosomes
The nucleus houses chromatin, which contains DNA, the genetic material. During division, chromatin becomes condensed into chromosomes.
The nucleolus is an area within the nucleus where ribosomal RNA is produced. Proteins are combined with the rRNA to form the subunits of ribosomes, which exit the nuclear envelope throughnuclear pores.
Ribosomes in the cytoplasm synthesize polypeptides using information transferred to the DNA by mRNA.
Endomembrane System
The endoplasmic