Chapter 3: Cells Flashcards
How do healthy cells differ from cancer cells?
A normal breast cell has thousands of HER2 receptors, but cells of one form of breast cancer may have millions.
What happens to a person’s cells when they have cancer?
As describe the abnormal cells form rumors or uncontrolled populations of cell that invade nearby cells.
How do biologist use this information to develop drugs to fight cancer?
Herceptin prevents binding to HER2 receptors.
Why are cells called the unit of life?
Within cells, highly coordinated biochemically activities carry out the basic functions of life.
What is a cell?
A cell is the smallest unit of life that can function independently.
Briefly outline the development of our understanding of the cell from Hooke to the 1950’s.
English physicist Robert Hooke melted stands of spun glass to create lens. He focused on any type of insect he could hold still. When he looked at the cork that was bark from a tree it looked like cubicles where monks studied. Although he did not realize he was the first person to see the outline of cells.
Outline the cell theory?
Originally had two main components: all organisms are made of one or more cells, and the cell is the fundamental of life.
What are the contributions of Schielden, Schwann and Virchow to the theory? Why is it a theory?
schlieden first noted that cells were the basic units of plants, and then Schwann compared animal cells to plants, After observing similarities in many different plant and animal cell, they concluded that cells were “elementary particles of organisms, the unit of structure and function.” Virchow proposed that all cells come from per existing cells. This idea contradicted spontaneous generation. It’s still evolving so it’s not set in stone.
Compare the workings and images produced by light, scanning electron and transmission electron microscope?
The compound microscope uses two or more lenses to focus visible light through a specimen.
A confocal microscope enhances resolution by focusing while or laser light through a lens to the object.
The transmission electron microscope sends a beam of electrons through a very thin slice of a specimen, using a magnetic field rather than a glass lens to focus the beam.
The scanning electron microscope scans a beam of electrons over the surface of a metal coated, three dimensional specimen.
What are the five characteristics common to all cells
DNA RNA Ribosomes Protein Cytoplasm Cell membrane
What is an organelle?
Organelles are departments which carry out specialized functions.
What is the relationship between surface area to volume?
That smaller objects have more surface area relative to their volume than do larger objects with the same overall shape.
What separates a cell from its surroundings?
Cell membrane
How does a membrane separate a cell from its surroundings?
The membrane separates the cytoplasm from the cell’s surroundings.
Describe the two regions of a phospholipid molecule?
Phospholipid molecule consist of a glycerol molecule attached to a hydrophilic phosphate head and two hydrophobic fatty acids.
