Chapter 2 - Cellular Activity Flashcards
What is Nucleolus?
It is made up mainly of RNA.
What is the Nucleus?
It contains most of the cell’s DNA.
What is a Cytoplasm?
It is the fluid in which the organelles of the cell are suspended.
What is the Golgi Apparatus?
It modifies and packages proteins for secretion from the cell.
What is the Endplasmic Reticulum?
It is the membranous channels that store and transport materials; it also provides a surface on which chemical reactions occurs.
What are Ribosomes?
They are the sites of protein synthesis.
What is the cell membrane?
It separates the cell contents from the surroundings.
What is the Mitochondria?
It is the site of the reactions of aerobic respiration.
What is the Cytoskeleton?
It is a framework of microfilaments and tubules that support the cell.
What are the nuclear pores?
They are the openings in the nuclear membrane through which large molecules can pass.
Why is the membrane called a Fluid Mosaic Model?
The membrane is said to be a fluid because the molecules if which it is made are constantly changing position and it is said to be mosaic because it is composed of many different kind of molecules.
Explain the structure of the cell membrane.
The membrane is composed of phospholipid molecules which contain a phosphate group; they are arranged in a bilayer. Each phospholipid molecule has a head that is hydrophilic, (water loving) and a tail that is hydrophobic (water hating). Heads outside and tails inside.
What are Channel proteins?
They are proteins that allow the transport of specific substances across the cell membrane.
What molecules are embedded in the phospholipid bilayer?
Protein molecules and cholesterol molecules.
What are functions of the cell membrane?
- A Physical Barrier
- The regulations of the passage of materials
- Sensitivity
- Support
How does the Sensitivity of the cell membrane work?
The cell membrane is the first part of the cell affected by any changes in the extracellular fluid. It also has receptors that are sensitive to particular molecules in its immediate environment.