Chapter 1: The Cell Flashcards
(38 cards)
What are the basic tenets of Cell Theory?
- All living things are composed of cells
- The cell is the basic functional unit of life
- Cells arise only from pre-existing cells
- Cells carry genetic information in the form of DNA, which is genetic material passed from parent to daughter cell
What is the total magnification of a microscope with an eyepiece (10x) and a 4x lense?
40x
What does the diaphragm of a microscope control?
It controls the amount of light passing through the specimen, which is important for image contrast
What does the coarse adjustment knob do?
It roughly focuses the image by moving the stage up and down
What does the fine adjustment knob do?
It finely focuses the image
Smaller range than the coarse adjustment knob
What is the major advantage of a phase contrast microscope over a compound light microscope?
You can visualize living organisms
takes advantage of differences in refractive indices
What is centrifugation?
A machine that spins at very rapid speeds in order to separate components based on their shape and density
What is the major difference between prokaryotes and eukaryotes?
Prokaryotes do not have nuclei, whereas eukaryotes do
What are the two most common shapes of bacteria?
Spherical “cocci”
Rod-shaped “bacilli”
Describe prokaryotic ribosomes and eukaryotic ribosomes
Prokaryotic ribosomes are smaller (subunits 30S and 50S)
Eukaryotic ribossomes are bigger (subunits 40 S and 60S)
What three proteins make up the eukaryotic cytoskeleton?
Actin filaments, intermediate filaments, and microtubules
Describe the cell membrane
Organized into a phospholipid bilayer that has hydrophobic tails facing inward and hydrophilic heads facing outward
What is the relationship between polarity of a molecule and its ability to cross the membrane?
The more nonpolar a molecule is, the easier it will be able to traverse the hydrophobic core of the cell membrane
Describe the nuclear envelope
A double membrane that maintains a nuclear environment separate and distinct from the cytoplasm
Where is ribosomal RNA (rRNA) synthesized?
in the nucleolus
What are the two types of ribosomes?
Free ribosomes and bound ribosomes (found in the endoplasmic reticulum)
What is the difference between the smooth and rough ER?
The rough ER is lined with ribosomes, whereas the smooth ER has no ribosomes
What are the functional differences between the smooth and rough ER?
The smooth ER works toward lipid synthesis and detoxification of drugs and poisons, wheras the rough ER is more directly involved in the productoin of protein products
What does the Golgi apparatus do?
It receives materials from the smooth ER and then repackages them to send to the cell surface
What do lysosomes do?
They take material brought in by endosomes and digest them using hydrolytic enzymes at a lowered pH (5)
They also play an important role in triggering autolysis (cellular suicide) by releasing their enzymes into the cell
Describe the structure of the mitochondria
Contains two layers: inner and outer membrane
The inner membrane has many infoldings known as cristae
Inside the inner membrane is the mitochondrial matrix
They also contain their own genes that replicate independently from the nucleus
What is the symbiotic theory of mitochondria?
Mitochondria are thought to have evolved from one prokaryotic organism ingesting another in a symbiotic relationship.
What is unique about the inheritance of mitochondria?
They are only inherited maternally
A woman with a mitochondrial disease will pass the disease on to all of her children
What are the two major types of microbodies found in the cell?
peroxisomes and glyoxysomes
