Cellular Biology Flashcards
What are the components of cell theory?
- All living things are composed of cells
- The cell is the basic functional unit of life
- The chemical reactions of life take place inside the cell
- Cells arise only from pre-existing cells
- Cells carry genetic information in the form of DNA. This genetic material is passed from parent cell to daughter cell.
What are the six kingdoms of living things?
- Bacteria
- Archaea
- Protista
- Fungi
- Plantae
- Animalia
What is the difference between prokaryotes and eukaryotes?
Eukaryotes possess membrane-bound organelles and are generally considered more complex than prokaryotes. Prokaryotes do not contain nuclei or membrane-bound organelles.
What structures do prokaryotes possess?
cell membrane, cytoplasm, genetic material, ribosomes
What structures do eukaryotes possess?
cell membrane, nucleus, ribosomes, endoplasmic reticulum, golgi apparatus, mitochondria, cytoplasm, vacuoles/vesicles, centrioles, lysosomes, cytoskeleton
What is the function of the cell membrane?
The cell membrane encloses the cell and exhibits selective permeability in order to regulate the passage of materials into and out of the cell.
What is the fluid mosaic model?
The fluid mosaic model states that the cell membrane consists of a phospholipid bilayer with proteins embedded throughout. The lipids and many of the proteins can move freely within the membrane.
What is the structure of the cell membrane?
The cell membrane consists of phospholipid molecules that are arranged such that the long, nonpolar, hydrophobic “fatty” chains of carbon and hydrogen face each other, with the phosphorus-containing, polar, hydrophilic heads facing outward toward the aqueous environment.
What is the cell membrane readily permeable to?
small, nonpolar, hydrophobic molecules
ex: oxygen
small polar molecules
ex: water
How do small charged particles cross the cell membrane?
through protein channels
How do charged ions and larger charged molecules cross the cell membrane?
with the assistance of carrier proteins
What is the function of the nucleus?
The nucleus stores DNA wound around structural proteins called histones. The nucleus is enclosed by the nuclear membrane.
What role do histones play during DNA replication?
DNA winds tightly around histones to compact chromatin into chromosomes.
What role do histones play during transcription?
DNA unwinds itself from the histones.
What happens in the nucleolus?
ribosomal RNA (rRNA) synthesis
How is DNA organized in prokaryotes?
in small circular chromosomes located in the nucleoid
What is the function of ribosomes?
to facilitate protein production
What is the function of rRNA?
After being synthesized in the nucleolus of eukaryotes, rRNA molecules can either function in the cytoplasm as unbound ribosomes or on the outer surface of the endoplasmic reticulum as bound ribosomes.
How do ribosomes differ in prokaryotes?
rRNA synthesis and ribosome function all occurs in the cytoplasm
What is the function of the endoplasmic reticulum?
The ER is a network of membrane-enclosed spaces involved in the transport of materials throughout the cell. Typically, the materials are destined to be excreted by the cell.
What are the two different kinds of ER?
rough ER and smooth ER
What is the difference between rough ER and smooth ER?
Rough ER contains ribosomes and plays a role in assembling proteins. Smooth ER does not contain ribosomes and is involved with metabolism and production of lipids.
What is the function of the Golgi apparatus?
The Golgi apparatus is the primary site for cellular trafficking. It receives vesicles and their contents from the smooth ER, modifies them, and repackages them into vesicles that are distributed to the cell surface for exocytosis.
What is the function of mitochondria?
Mitochondria are the sites of aerobic respiration within the cell. They convert sugars, fats, and other fuel sources into usable energy in the form of adenosine triphosphate (ATP).
What does the outer membrane of the mitochondria do?
forms a barrier with the cytosol
What does the inner membrane of the mitochondria do?
folded into cristae and contains enzymes for the electron transport chain
Where is the genome of mitochondria located?
in the mitochondrial matrix
How is mitochondrial DNA different from nuclear DNA?
Mitochondrial DNA is independent of the cell genome and looks like circular bacterial chromosomes. This allows mitochondria to divide independently of the nucleus via binary fission.
What is the function of the cytoplasm?
The cytoplasm contains all of the cell’s organelles and the cytosol (cellular fluid). It is the site of most of the cell’s metabolic activity.
What is cyclosis?
transport within the cytoplasm
What is the function of vacuoles/vesicles?
Vacuoles and vesicles are membrane-bound sacs that are involved in the transport and storage of materials that are ingested, secreted, processed, or digested by the cell.
What is the difference between vacuoles and vesicles?
Vacuoles are larger and more likely to be found in plant cells than in animal cells.
What is the function of centrioles?
Centrioles are made up of microtubules and are involved in spindle organization during cell division.
What is the function of the centrosome?
The centrosome is the region of the cell where the centrioles are located. It organizes the microtubules to help regulate the progression of the cell cycle.
Which kind of cells do not contain centrioles?
plant cells
What is the function of lysosomes?
Lysosomes are membrane-bound vesicles that contain hydrolytic enzymes involved in intracellular digestion. They break down material that is ingested by the cell.