1.2 (Topic 1) Flashcards
(39 cards)
Outline the major difference between prokaryotic and eukaryotic cells
Prokaryotic Cells
- Smaller (about 0.2 - 2 um)
- DNA in nucleoid region (no nuclear membrane)
- No membrane bound organelles
- Cell wall of peptidoglycan
- Smaller ribosomes (70s) in cytoplasm
- DNA is circular and without histone proteins
- Has plasmid DNA
- Asexual cell division
Eukaryotic Cells
- Bigger (10-100 um)
- DNA in a true nucleus
- Membrane bound organelles present
- Cell wall of cellulose (plants) or chitin (fungus)
- Larger ribosomes (80s) in cytoplasm and on ER (also has 70s ribosomes within mitochondria and chloroplasts)
- DNA is linear with histone proteins
- Do not have plasmid DNA
- Asexual or sexual cell division
List the structures of a prokaryotic cell
Cell membrane Nucleoid Plasmid Cytoplasm Ribosome Cell wall Pilli Capsule Flagella
List the function of the cell membrane of a prokaryotic cell
- forms the boundary of the cell
- acts as a selective barrier, allowing certain materials to pass into and out of the cell, but not others
List the function of the nucleoid of a prokaryotic cell
- location of the genetic material for inheritance and protein coding
- circular DNA
- not associated with histone proteins
List the function of the plasmid of a prokaryotic cell
- smaller, circular DNA not associated with DNA in the nucleoid
- often contains genes for antibiotic resistance
List the function of the cytoplasm of a prokaryotic cell
- primarily water and dissolved molecules
the location of many metabolic reactions
List the function of the ribosome of a prokaryotic cell
- responsible for catalyzing the formation of polypeptides during protein synthesis
- size is 70s
List the function of the cell wall of a prokaryotic cell
- found in most prokaryotic cells
- provides shape and protection to the cell
- composed of peptidoglycan
List the function of the pilli of a prokaryotic cell
- found in some (not all) prokaryotic cells
- provides shape and protection to the cell
- help the cell attach to surfaces
List the function of the capsule of a prokaryotic cell
- found in some (not all) prokaryotic cells
- helps the cel maintain moisture and adhere to surfaces
- protects the cells from other organisms
List the function of the flagella of a prokaryotic cell
- found in some (not all) prokaryotic cells
- long extension used for cell locomotion
Contrast the size of eukaryotic and prokaryotic ribosomes.
Prokaryotes have a smaller, 70s ribosome.
Eukaryotes have a larger, 80s ribosome.
The mitochondria and chloroplasts within eukaryotic cells have 70s ribosomes.
(The “s” stands for Svedberg unit, a measure of particle sedimentation rate)
State the meaning and advantages of eukaryotic cells being “compartmentalized.”
Compartmentalization is the presence of membrane bound partitions (organelles) within the eukaryotic cell. The compartments allow for:
Specialization of regions within the cell for specific functions.
Molecules needed for a specific function to be concentrated in a region within the cell.
State structural differences between plant and animal cells.
Animal Cells - No cell wall - No chloroplasts - No large vacuole = Not a fixed shape - Stores carbohydrates as glycogen
Plant Cells - Cell wall - Chloroplasts Large vacuole - Fixed shape - Stores carbohydrates as starch
Define asexual reproduction.
- Asexual reproduction creates offspring from a single parent organism. - - The offspring are genetic clones of that parent.
Outline the four steps of binary fission.
- The nucleoid DNA replicates to create an exact duplicate copy.
- The nucleoid DNAs attach to the cell membrane.
- The cell membrane (and wall, if present) grow, causing the cell to elongate and the DNA molecules to move apart from each other.
- The cell membrane pinches inward, creating two genetically identical cells.
Define resolution.
The smallest interval distinguishable by the microscope, which then corresponds to the degree of detail visible in an image created by the instrument.
Compare the functionality of light and electron microscopes.
- LIGHT MICROSCOPES*
- Use lenses to bend light and magnify images.
- Used to study dead or living cells in color.
- Cell movement can be studied.
- Larger field of view.
- Objects can be magnified up to 2000X.
- Can resolve objects 200 nm apart.
- ELECTRON MICROSCOPES*
- Uses electron beams focused by electromagnets to magnify and resolve.
- Requires cells to be killed and chemically treated before viewing.
- No movement can be seen.
- Without stain or dye, no color can be seen.
- Smaller field of view.
- Can magnify objects up to 250,000 times.
- Can resolve objects that are 0.2 nm apart.
State the function of an exocrine gland cell.
- Exocrine gland cells synthesize molecules (often proteins) for secretion from the cell into an external space.
- Exocrine gland cells of the pancreas secrete enzymes that function in digestion in the small intestine.
List the structures in an exocrine gland cell (eukaryotic cell)
plasma membrane nucleus mitochondria golgi apparatus lysosome endoplasmic reticulum
List the function of the plasma membrane in an exocrine gland cell (eukaryotic cell)
from the boundary of the cell, acts as a selective barrier allowing certain materials to pass into and out of the cell
List the function of the nucleus in an exocrine gland cell (eukaryotic cell)
contains most of the genes that control the eukaryotic cells, contains the nucleolus and chromatin
List the function of the mitochondria in an exocrine gland cell (eukaryotic cell)
the location of aerobic cellular respiration used to make ATP
List the function of the golgi apparatus in an exocrine gland cell (eukaryotic cell)
consists of flattened membranous sacs; receives transport vesicles from the ER, modifies proteins produced in the ER, produces secretory vesicles
