Module 1: The Cell Flashcards
The ______ is the basic unit of life.
The CELL is the basic unit of life. A cell is the smallest unit that can carry out all activities we associate with life.
When provided with essential ___________ and an appropriate ______, some cells can be kept alive and growing for many years.
When provided with essential NUTRIENTS and an appropriate ENVIRONMENT, some cells can be kept alive and growing for many years.
True or False:
No isolated part of a cell is capable of sustained survival.
TRUE.
Are human beings uni-cellular organisms or multi-cellular organisms?
Human beings are multi-cellular organisms.
Name a type of uni-cellular organism.
Bacteria are a uni-cellular organism.
What is the cell theory?
Biologists realized by the middle of the nineteenth century that cells are the basic living units of organization and function in all organisms and that all cells come from other cells. This is called the cell theory.
Whose work established the cell theory in the middle of the nineteenth century?
German Scientists, Schleidan, Schwann, and Virchow created cell theory.
Most cells are too small to be seen with the eye alone. They require magnification.
What is the device that passes light through a thin sample of the cell medium and then through a magnifying lens to be seen by the human eye?
A light microscope. It’s a device that passes light through a thin sample of the cell medium and then through a magnifying lens to be seen by the human eye.
Few cells are as big as _______ (mm) in diameter (which is about _____th of an inch) and are large enough to be seen by the human eye.
Few cells are as big as one millimeter (mm) in diameter (which is about 1/25th of an inch) and are large enough to be seen by the human eye. Think, for example, of a frog’s egg.
What is a biomacromolecule?
What is an organelle?
Can either of these be seen by the human eye?
Organelles (parts within a cell), and Biomacromolecules (proteins, lipids, carbohydrates, and nucleic acids) from which they are composed are too small to be seen without the aid of a microscope.
Organelles are to a cell what an organ is to a human.
What two processes can organelles be used for?
Organelles can be used for
1) energy conversion and
2) for synthesis of needed compounds
Why are cells so small?
Cells must take in food and other materials and rid themselves of _______.
Why are cells so small? Cells must take in food and other materials and rid themselves of waste.
Everything that enters or leaves a cell must pass through its ________.
Everything that enters or leaves a cell must pass through its PLASMA MEMBRANE.
What is the function of the plasma membrane as it surrounds all cells?
The plasma membrane surrounds all cells and contains specialized “pumps” and “gates” that regulate the passage of materials in and out of the cell.
What contains specialized “pumps” and “gates”?
The plasma membrane surrounds all cells and contains specialized “pumps” and “gates” that regulate the passage of materials in and out of the cell.
What changes as a cell grows?
As a cell grows, the surface-area-to-volume ratio changes.
Why do cells need to remain small?
Which size of cell is more active? the smaller or bigger cell?
Cells need to remain relatively small because, as a cell expands, the amount of surface area relative to the volume of the cell decreases.
The smaller cell is more active because, relative to its volume, its surface area is larger than a bigger cell.
Having a larger surface area (than large volume) allows what to happen faster?
Metabolic processes.
With a larger surface area (relative to its volume) this allows the metabolic processes to occur faster.
Name a type of metabolic processs, which is one that can occur faster with a cell with a ________ surface area.
DIFFUSION is a metabolic processes.
Larger surface area allows diffusion to occur faster.
What is diffusion?
Diffusion is the transportation of particles across the membrane.
Name a type of adaptation that cells and organelles have in addition to their small size that great greatly increase their surface area.
Cells (like those of the intestinal wall) and organelles (like the mitochondria) that are actively carrying out biochemical processes have adaptations (like NUMEROUS FOLDS) in addition to their small size that greatly increase their surface area.
What are the two basic types of cells?
The two basic types of cells are prokaryotic and eukaryotic cells.
Name a type of prokaryotic cell.
Bacteria are prokaryotic cells.
What does the word prokaryotic mean?
(prokaryotic means “before the nucleus”)
Prokaryotic cells are considered simple cells for 3 reasons:
Prokarytoic cells are:
1) typically smaller than eukaryotic cells. Most are between 1-10 μm (micrometers) in size (about 1/30,000 of an inch); therefore, they are just visible with the light microscope.
2) The DNA of a prokaryotic cell is not enclosed in a nuclear membrane (prokaryotic means “before the nucleus”).
3) Prokaryotic cells do not contain many of the internal membrane-bound organelles of eukaryotic cells. Like eukaryotic cells, prokaryotic cells contain a plasma membrane and ribosomes.
What is the typical size of prokaryotic cells? About 1/_______ th of an inch.
How can prokaryotic cells be viewed?
a) human eye?
b) only light microscope
Most prokarytoic cells are between 1-10 μm (micrometers) in size (about 1/30,000 of an inch); therefore, they are just visible with the light microscope.
What two things do prokaryotic cells and eukaryotic cells contain?
Like eukaryotic cells, prokaryotic cells contain a
1) plasma membrane and
2) ribosomes.
Ribosomes:
What are ribosomes composed of?
What do ribosomes synthesize?
Ribosomes are composed of ribonucleic acid (RNA) and synthesize proteins for use by the cell
True / False.
Ribosomes are NOT surrounded by a membrane.
TRUE. Ribosomes are not surrounded by a membrane. Membranes provide a location for metabolic processes to occur. Because prokaryotes lack organelles with membranes, the plasma membrane of a prokaryotic cell is often folded inward to create numerous folds where metabolic processes take place.
Notes only:
Most people think of bacteria as causing diseases. An example is botulism, a type of food poisoning that can lead to paralysis and sometimes death. This bacterium, Clostridium botulinum, can form a dormant, extremely durable cell called an endospore, which is released by the bacterium under adverse conditions. During the canning process, food must be heated to boiling for 3 to 4 minutes to kill any highly heat-resistant endospores that might be present.
Notes only:
Most people think of bacteria as causing diseases. An example is botulism, a type of food poisoning that can lead to paralysis and sometimes death. This bacterium, Clostridium botulinum, can form a dormant, extremely durable cell called an endospore, which is released by the bacterium under adverse conditions. During the canning process, food must be heated to boiling for 3 to 4 minutes to kill any highly heat-resistant endospores that might be present.
What kind of cells do plants, animals and humans all possess?
Plants, animals, and humans all possess eukaryotic cells.
Which is larger?
A prokaryotic cell? or a eukaryotic cell?
What is the typical size of a eukaryotic cell?
Eukaryotic cells (complex cells) are 10 to 100 times larger than prokaryotic cells,
What does the word Eukaryotic mean?
Eukaryotic cells possess a nuclear membrane (eukaryotic means “true nucleus”), and contain many membrane-bound organelles.
What are some ways that membranes are important to complex cells?
Membranes are important to a complex cell for many reasons, such as:
1) the forming of compartments within organelles where reactants are more likely to come into contact or keep certain compounds away from one another.
2) Membranes also form a work surface where many enzymes can congregate to complete a complex reaction.
Eukaryotic cells have ___________ inside each cell.
Eukaryotic cells have ORGANELLES inside each cell.
What is the most prominent organelle in a cell?
The NUCLEUS, surrounded by a nuclear membrane (envelope), is the most prominent organelle in the cell.
In the Euraryotic cell, what does the nucleus contain?
What does the nucleus serve as for the cell?
The nucleus contains DNA
The nucleus serves as the control center of the cell.
What organelle serves as the CONTROL CENTER of the Eurakraytic cell?
The NUCLEUS surrounded by a nuclear membrane (envelope), is the most prominent organelle in the cell It contains DNA and serves as the control center of the cell.
