Ch. 1: The Cell Flashcards
What are the components of 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 contain genetic information (DNA) passed onto daughter cells
Viruses contian genetic information but cannot reproduce on their own
What is the difference between prokaryotes and eukaryotes?
prokaryotes do not have membrane bound organellse have have their genetic material in a single circular molecule of DNA in the nucleoid region
eukaryotes have membrane bound organelles, a nucleus, and form multicellular organisms
What is the organization and function of the nucleus?
and Nucleolus
the nucleus contians the genetic information and acts as the control center, it is surrounded by a double membrane (nuclear membrane) that contains nuclear pores that allow exchange between the cytosol and nucleus
Nucleolus is located in the nucleus and synthesizes ribosomal RNA
What is the organzation and function of mitrochondria?
- outer membrane seperates cytosol and inner mitochondrion
- inner membrane has many folds call cristae and contains molecules and enzymes for electron transport chain
- intermembrane space is between the membranes
- mitochondrial matrix is inside inner mitochondiral membrane
mitochondria have some of their own DNA so they can replicate independently of nucleus by binary fission
are able to release enzymes to start cell death
What is the function of lysosomes?
lysosomes contain hydrolytic enzymes that break down substrates
they work with endosomes which transport and package materials going in and out of the cell
the lysosomal membrane may open to release the enzymes for apoptosis – “autolysis”
What is the function of the endoplasmic reticulum?
Rough ER has ribosomes allowing for translation of proteins to be secreted into lumen.
Smooth ER is responsible for lipid synthesis and detoxification of some drugs.
ER is a series of interconnected and folded membranes.
What is the function of the golgi apparatus?
they are a stack of membrane bounds sacs that modify materials by adding carbs, phosphates, and sulfates or by adding signal sequences to direct delivery
the materials travel from the ER in vesicles to the golgi
What is the function of peroxisomes?
peroxisomes contain hydrogen peroxides to break down long fatty acids in B-oxidation and participate in phospholipid synthesis and the pentose phosphate pathway
What is the function of the cytoskeleton?
- cell structure and maintain shape
- conduit of transport of materials around the cell
Component of the Cytoskeleton
What are microfilaments?
Microfilaments are solid rods of actin that protect the cell by being resistant to compression and fracture.
They also play a role in cytokinesis and may use ATP in conjuction with myosin for muscle movement.
Component of the Cytoskeleton
What are microtubules?
Cilia? Flagella?
Microtubules are hollow tubulin proteins that provide pathways for motor proteins like kinesin and dynein.
They also form a 9+2 structure for cilia (projections from a cell to move materials along cell) and flagella (move the cell itself). 9 microtubules as an outer ring and 2 in the center?
Component of the Cytoskeleton
What are intermediate filaments?
They are responsible for cell-cell adhesion and maitenance of the cytoskeleton by helping anchor organells.
Ex. Keratin and desmin
What is the function of epithelial tissue?
Epithelial cells conver the body and line its cavities and protects agains pathogen invasion and desiccation. It may also be involved in absorption, secretion, and sensation. They are diverse and function depends on the organ. They are often polarized so that one side faces the lumen and the other blood vessels/structure.
- Basement membrane is the underlying layer of connective tissue.
- Simple epithelia have one layer of cells
- Stratified epithelia have multiple layers
- Pseudostratified epithelia are only one layer but appear to have multiple layers (differences in height)
Parenchyma - act in the function of the organ
Cuboidal (cube), columnar (column), or squamous (flat) shaped.
What is the function of connective tissue?
Connective tisue supports the body and provides the framework for the epithelial cells. Most cells secrete collagen and elastin to for the extracellular matrix.
Stroma - act to support the structure of the organ
Ex. Bone, cartilage, tendons, ligaments, adipose tissue, blood
Prokaryotes
Describe Archaea.
How are they similar to bacteria and eukaryotes?
- single celled organisims
- extremophiles that live in harsh environemnts and use chemical sources of energy
- singular circular chromosome that divides by binarry fission or budding
Like bacteria, archaea are single celled with no nucleus or membrane organells and have a single circular chromosome and repreoduce through binary fission. Like eukaryotes, archaea start translation with emthionine.