Biology: Chapter 1: The Cell Flashcards
What are the tenets of Cell Theory
1) All living organisms are made up of cells
2) Cells are the basic functional unit
3) Cells are made from pre-existing cells
4) Cells contain genetic information in the form of DNA
Why are viruses not considered living organisms?
Viruses violate tenets 3 and 4 of the cell theory: They cannot reproduce alone (require the host cell) and they do not have DNA
What are Eukaryotic cells
Cells with a nucleus, membrane bound organelles, and unicellular/multicellular
What is the cytosol
fluid that suspends the organelles and allows for diffusion of molecules throughout the cell
what is the nucleus
contains DNA in the form of chromosomes; surrounded by nuclear envelope; site of transcription
what are nuclear pores
pores in the nuclear envelope that allow for two-way exchange of materials between the nucleus and the cytosol
what is the nucleolus
subsection of nucleus where RNA is synthesized (transcription)
what is the mitochondria
powerhouse of the cell; divide independently via binary fission; trigger apoptosis by releasing mitochondrial enzymes
what are lysosomes
Contain hydrolytic enzymes to break down molecules ingested by endocytosis; autolysis happens if these enzymes are released into cytosol
what is the rough endoplasmic reticulum
contains ribosomes; site of protein synthesis
what is the smooth endoplasmic reticulum
lipid synthesis; detoxication;
moves proteins from RER -> Golgi Apparatus
what is the Golgi Apparatus
modifies, packages, and secretes proteins
what are peroxisomes
contains H2O2; breaks down fatty acid chains via beta oxidation; lipid synthesis; contribute to pentose phosphate pathway
what are the components of the cytoskeleton
microfilaments
microtubules
intermediate filaments
what are microfilaments
made up of actin; provide structural protection for the cell and cause muscle contraction when interacting with myosin; formation of cleavage furrow during mitosis
what are microtubules
made up of tubulin; create pathways for vesicle movement; make up cilia and flagella
what is the 9 + 2 arrangement for flagella
9 outer microtubules and 2 center microtubules
What are intermediate filaments
cell to cell adhesion and maintenance of the integrity of cytoskeleton; anchor organelles; examples keratin and desmin
what is epithelial tissue
cover the body and line cavities; protect against pathogen invasion; absorb/secrete substances; participate in sensation; parenchyma; polarized (inner lumen and outer membrane)
what are the classifications of epithelial tissue
simple –> one layer
stratifies –> multi-layer
pseudo stratified –> looks like multiple layers but is one
what are the types of epithelial tissue shapes
cuboidal –> cubed
columnar –> long and narrow
squamous –> flat and scale like
what is connective tissue
support the body and provide framework for epithelial cells; stroma; secrete materials to form extracellular matrix