Unit 2 Study Guide Flashcards
What is a eukaryote? Most common example?
Cells with membrane bound organelles; have a clear nucleus. Ex. plants and animals
What is a prokaryote? Most common example?
No membrane bound organelles; no clear nucleus. Ex. bacteria
What types of organisms have a cell wall?
Plants, bacteria, and fungi
How do you find the total magnification on a microscope?
Multiply the magnification of the objective lens by the magnification of the eyepiece lens
What did Schleiden and Schwann figure out about cells?
The Cell Theory
Who was the first person to see a cell?
Robert Hooke
Who was the first person to see a living cell?
Anton Van Leeuwenhoek
What are the three points of the Cell Theory?
- All living things are composed of cells
- The cell is the basic unit of life
- New cells come from existing cells
What is the difference between compound and electron microscopes?
Electron microscopes can magnify cells at a much greater magnification
What is an organelle?
A structure in the cell with a specific job
What material is found in the nucleus of a cell?
DNA, chromatin, chromosomes
What is the function of the cell wall and what is it made of?
The cell wall gives the cell structure and protection.
It is made of cellulose and pectin.
What is the function of the cell membrane and what is it made of?
The cell membrane regulates the transport of materials entering and exiting the cell.
It is made of lipids and proteins.
Which organelle provides the cell with energy?
Mitochondria
Which organelle makes proteins?
Ribosomes
Which organelle packages and sorts proteins?
Golgi Body
Which organelle temporarily stores substances?
Vacuoles
Which organelle makes food?
Chloroplasts
Which organelle transports proteins?
ER
Which organelle breaks down cellular waste and used parts?
Lysosomes
What are the two main components of in the cell membrane?
Lipids and proteins
Why is the cell membrane referred to as the fluid mosaic model?
The cell membrane is made of different parts working together, like a mosaic is made of many tiles
What does it mean that the cell membrane is selectively permeable?
Selective permeability means the cell membrane decides what passes in and out.
Diffusion moves from and area of ______________ to ____________ concentration.
High to Low
Compare and contrast passive and active transport in terms of energy and direction of the
concentration gradient.
In active transport, the molecules move against the concentration gradient whereas in passive transport, the molecules move along the concentration gradient
How is simple diffusion different from facilitated diffusion?
In simple diffusion, the substance passes between the phospholipids; in facilitated diffusion there are a specialized membrane channels.
What kind of molecules must use
facilitated diffusion to pass across the membrane?
Charged or polar molecules that cannot fit between the phospholipids generally enter and leave cells through facilitated diffusion.
What kinds of molecules
can EASILY pass through the membrane?
Hydrocarbons and oxygen easily pass through
When molecules are equally distributed across an area, that area is said to be in what?
In equilibrium
Explain what is happening to a cell that increases in size in terms of osmosis. (What direction is
the water flowing in? What kind of solution is the cell floating in?)
The cell is hypotonic, in, hypertonic
What happens when you put a cell into a hypertonic solution? Pure water?
A cell placed into a hypertonic solution will shrivel and die by a process known as plasmolysis. water will diffuse into the cell and the cell will begin to swell
Compare and contrast exocytosis and endocytosis.
Endocytosis is the process of capturing a substance or particle from outside the cell by engulfing it with the cell membrane, and bringing it into the cell. Exocytosis describes the process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell.
How is one cell in a multi-cellular organism different from a unicellular organism?
Unicellular organisms are made up of only one cell that carries out all of the functions needed by the organism, while multicellular organisms use many different cells to function.
What is the cell wall composed of?
The cell wall is composed of a network of cellulose microfibrils and cross-linking glycans embedded in a highly cross-linked matrix of pectin polysaccharides
Which stage of cell signaling is a transcription protein activated for gene regulation?
Compare and contrast the mitochondria and the chloroplast
Mitochondria are the “powerhouses” of animal cells, while chloroplasts are the “powerhouses” of plant cells.
Describe a phospholipid in terms of polar and non-polar
Phospholipid heads are polar, and the tails are non-polar
