Biology Chapter 1: The Cell Flashcards
What are the four parts of the cell theory?
- All living things are composed of cells.
- The cell is the basic functional unit of life.
- Cells arise only from preexisting cells.
- Cells carry genetic information in the form of DNA. This genetic material is passed on from parent to daughter cell.
Why are viruses not considered living things?
- Acellular
- Cannot reproduce without the assistance of a host cell, and may contain RNA as their genetic material
What is the nucleolus?
a subsection of the nucleus in which ribosomal RNA is synthesized
What does the release of mitochondrial enzymes into the cytoplasm do?
triggers apoptosis
What is the rough ER used for?
Has ribosomes on it, so used for translation of proteins
What is the smooth ER used for?
lipid synthesis and detoxification
What is the golgi apparatus?
It is membrane bound sacs in which cellular products can be modified, packaged, and directed to specific cellular locations
What are peroxisomes?
Contain hydrogen peroxide and can break down very long chain fatty acids via beta-oxidation. They also parrticipate in phospholipid synthesis and the pentose phosphate pathway.
What are microfilliments composed of? What do they do?
Actin - They provide structural protection for the cell. and can cause contraction through interactions with myosin, also help create the cleavage furrow during cytokinesis in mitosis.
What are microtubules composed of? What do they do?
They are composed of tubulin. they create pathways for motor proteins, such as kinesin and dynein. They also contribute to the structure of cilia and flagella.
How are cilia and flagella organized?
Into 9 pairs of microtubules in a ring with two in the center.
Where are centrioles found? How are they used?
In centrosomes and are involved in microtubule organization in the mitotic spindle.
What are intermediate filaments used for?
cell-cell adhesion or maintenance of the integrity of the cytoskeleton; they help anchor organelles. Common examples include keratin and desmin.
What are epithelial tissues?
Cover the body and line cavities
What are the parenchyma?
Functional parts of the organ, usually made up of epithelial cells.
Are epithelial cells charged?
Sometimes they may be polarized, one side facing a lumen and the other side facing blood vessels and structural cells.
What is the difference between simple, stratified and psuedostratified epithelia?
Simple = 1 layer Stratified = Multiple layers Psuedostratified = appear to have multiple layers because of difference in cell heights, but actually only have one layer.
What are the three types of epithelia classifications?
cubioidal (cube-shaped), columnar (long and narrow), squamous (flat and scale-like)
What is the stroma?
Support structure