Ch 3 Cellular level of organization Flashcards
what is the cell theory
Cell theory
1cells are the building blocks of all organisms
2 all cells come from the division of preexisting cells
3cells are the smallest units that perform all vital physiological functions
4 each cell maintains homeostasis at the cellular level
What are the two types of cells
Sex cells and sematic cells
What is the plasma membrane
The plasma membrane or cell membrane separates cytoplasm from extracellular fluid
What are the functions of the plasma membrane
Physical isolation
Regulation of exchange with the environment
Sensitivity to the environment
Structural support
What is the phospholipid bilayer
Makes up the cell membrane it is two layers of phospholipids
Integral proteins
Are proteins within the membrane they also outnumber peripheral proteins
Peripheral proteins
Bound to enter or outer surfaces of the membrane
Anchoring proteins
Are used to stabilize the position of the cell
Recognition proteins
Also called identifiers, they label the cells as normal or abnormal this is very important to the immune system
Enzymes
Catalyzed reactions
Receptor proteins
Find and respond to ligands (ions, hormones)
Carrier proteins
Transport specific solutes through the membrane
Channels
Regulate water flow and solutes passing through the membrane gated channels open or close to regulate passage of the substances
Cytoplasm
All materials inside the cell and outside of the
Cytosol
Also called intracellular fluid is a mixture of water and various insoluble and dissolved materials
Organelles
Structures with specific functions better inside the cell
Non-membranous organelles
They have no membrane and direct contact with the cytosol some examples are the cytoskeleton centrioles ribosomes proteasomes microvilli cilia and flagella
Membranous organelles
Are isolated from cytosol by a plasma membrane
Some examples are the endoplasmic reticulum the Golgi apparatus lysosomes peroxisomes and mitochondria
How do the cytosol and extracellular fluid differ
The levels of sodium and potassium are different
The suspended protein concentration differ
And nutrient concentrations differ
Inclusions
Masses of insoluble material in cells
Cytoskeleton
Structural proteins for shape and strength
Microfilaments, intermediate filaments, microtubules are what make up the cytoskeleton
Microfilaments
Thin filaments composed of the protein actin
This provides mechanical strength it interacts with other proteins to ingest consistency of the cytosol and interacts with thick filaments of myosin for muscle contractions it also helps anchor the cytoskeleton
Intermediate filaments
Mid-sized between microfilaments and microtubules most durable part of the whole cytoskeleton they stabilize the position of the organelles and the cell position