What is a cell?
A cell is the smallest living functional unit of an organism.
What are cells composed of?
Living cells are
composed of approximately 60% water and vary in size and shape.
How is a red blood cell shaped?
Disc shaped. Biconcave discs.
how is a nerve cell shaped?
whereas nerve cells can be very long and have extensions on their main
body.
What does the nucleus do?
The nucleus contains the genetic information, or DNA (deoxyribonucleic acid), and controls
the activities of the cell.
What is the plasma cell membrane?
The plasma (or cell) membrane is known as a semipermeable membrane that separates the contents of the cell from the surrounding fluid
What does the interstitial fluid contain?
The interstitial fluid contains substances such as amino acids, sugars, fatty acids,
hormones, neurotransmitters, and salts
What does selectively permeable mean?
The term, selectively permeable (semipermeable),
refers to the selective nature of the plasma membrane. It contains pores and channels that
allow only particles of the right size or the right chemical nature to pass through. Additionally,
the plasma membrane contains receptors that bind with specific substances, thus allowing for
special entry or signals the cell to perform a certain activity.
What is the cytoplasm?
The cytoplasm is the fluid matrix found between the plasma membrane and the nucleus that
acts as scaffolding for the organelles.
What are the organelles
Organelles, or “little organs,” are specialized units in the
cell that perform certain functions.
What are the mitochondria?
The mitochondria are the locations for cellular respiration
or the conversion of food to energy at the cellular level. Thus the mitochondria are the sites of
energy production and of most of its ATP (adenosine triphosphate), which is a chemical the
cell uses to store and transfer energy within itself
What are ribosomes?
Ribosomes are the sites of protein
synthesis in the cell.
What does the rough ER do?
Rough ER, named for the fact that it has ribosomes on its surface,
serves to store and deliver the proteins made by the attached ribosomes.
What does the smooth ER do?
Smooth ER is free of
ribosomes and is found in a variety of cells. It performs varying functions in different cells,
including the storage of enzymes and minerals and the folding of proteins. It is thought to be
involved in the detoxification of chemicals and the metabolism of fats.
What does the golgi complex do?
The Golgi complex
modifies and packages proteins destined for use in the cell or for export from the cell.
What do lysosomes do?
Lysosomes are sacs that contain strong digestive enzymes. These sacs are responsible for
digesting waste and cell structures that are malfunctioning or dead.
How can plant cells be distinguished from animal cells?
Plant cells can be distinguished from animal plants by the presence of a surrounding cell wall
and chloroplasts.
What does the cell wall do?
The cell wall is essential for protection of the cell, the maintenance of the
shape, and water balance.
What are chloroplasts?
Chloroplasts contain chlorophyll, which is necessary for
photosynthesis
What are vacuoles?
Plant cells also often have large vacuoles, which are compartments in the
cytoplasm that act as places for secretion, excretion, and storage
Why do cells divide?
Cells divide for a number of reasons: growth, repair, and the production of gametes (sperm or
egg cells).
What is the most important part of cell division?
The most important result of cell division is that the genetic material, DNA, is
transmitted to the offspring.
What is chromatin?
When a cell is not dividing, DNA is found in the form of loosely structured
chromatin,
What is chromosomes?
but when a cell is dividing, the DNA is seen in condensed rod-shaped bodies
called chromosomes.