Cell Anatomy Flashcards
What is cell theory
-the cell is the smallest structural and functional living unit
what do the organismal functions of cells depend on
-individual and collective cell functions
what are the biochemical activities of cells dictated by
-their specific subcellular complementarity
-e.g. form dictates functions… anatomy leads to physiology
what are the two basic cell types
Prokaryotes: single-celled organisms
Eukaryotes: Present in milti- cellular organisms (make us up
what are the functions of cells
-Metabolize and release energy
-Synthesize molecules
-Reproduction and Inheritance
-Provide a means of communication
how do cells metabolize and release energy
-chemical reactions that occur within cells
-release of energy in the form of ATP helps maintain body temperature
how do cells synthesize molecules
cells differ from each other because they synthesize different kinds of molecules (create proteins and hormones)
how do cells Provide a means of communication
-(neurons communicate w/rest of body
achieved by chemical and electrical signaling
how do cells provide reproduction and inheritance
Mitosis- division resulting 2 identical daughter cells
Meiosis- creates egg and sperm cells (4 different daughter cells) still divides the cells
what three basic parts of a human cell
-plasma membrane: flexible outer boundary
-intercellular fluid (cytosol) containing organelles
- cytoplasm
what is the plasma membrane and what does it do
-Bimolecular layer of lipids and proteins in a constantly changing fluid mosaic
-Plays a dynamic role in cellular activity
-Separates intracellular fluid (ICF) from extracellular fluid (ECF)
-Interstitial fluid (IF) = ECF surrounding cells
Describe membrane lipids
75% phospholipids (lipid bilayer):
5% glycolipids:
Lipids with polar sugar groups on outer membrane surface
20% cholesterol:
Increases membrane stability and decreases mobility
The more cholesterol the less movable the membrane is
what are the 3 membrane junctions
-Tight junction
-Desmosome
-Gap junction
what are tight junctions
-Impermeable junctions prevent molecules from passing through the intercellular space
-Found in the skin or the GI tract
what are desmosomes
-Anchoring junctions bind adjacent cells together and help form an internal tension-reducing network of fibers.
-Difficult to pull apart but there could still be space, we would find this in the muscles and in the skin
what are gap junctions
Communicating junctions allow ions and small molecules to pass from one cell to the next for intercellular communication allows one cell to communicate with another
what is cytoplasm
-Between plasma and nucleus
Cytosol:
Water with solutes, proteins, salts, sugars, etc
Cytoplasmic organelles:
Metabolic machinery of cell
what are the membranous organelles
-Mitochondria
-Endoplasmic reticulum
-Golgi apparatus
-Lysosomes
-Peroxisomes
-Membranes allow compartmentalization, crucial to cell function
what is the mitochondria
-the powerhouse of the cell
-Double-membrane structure
-Provide most of cell’s ATP via aerobic cellular respiration
-ATP=molecule that stores and releases energy
-Contain their own DNA and RNA
what are the ribosomes and the different types
-Granules containing protein and rRNA
-Site of protein synthesis
Types:
-Free ribosomes - synthesize soluble proteins
-Membrane-bound ribosomes (on rough ER) - synthesize proteins to be incorporated into membranes or exported from cell
what is the endoplasmic reticulum and the two different types
-Interconnected tubes and parallel membranes enclosing cisternae
Continuous with nuclear membrane
Two varieties:
1. Rough ER- synthesizes membrane integral proteins and phospholipids. Manufactures all secreted proteins
2. Smooth ER
what are the lysosomes
-the trash cans
-Spherical membranous bags containing digestive enzymes (acid hydrolases)
-digest ingested bacteria, viruses, and toxins
-degrade nonfunctional organelles
-Break down and release glycogen
-Break down bone to release Ca2+
-destroy cells in injured or non-useful tissue (autolysis)
what are peroxisomes
-the recycling bin
-Membranous sacs containing powerful enzymes (e.g.,oxidases and catalases)
-Detoxify harmful or toxic substances
-Neutralize dangerous free radicals (highly reactive chemicals with unpaired electrons)
What is the nucleus
-genetic library with blueprints for nearly all cellular proteins
-Responds to signals and dictates kinds and amounts of proteins to be synthesized
-Most cells are uninucleate
-Red blood cells are anucleate
what is the nuclear envelope
Double-membrane barrier containing pores (large molecule transport)
what is the nucleoli
-Dark-staining spherical bodies within nucleus
-Involved in rRNA synthesis and ribosome subunit assembly
