Ch 3 Flashcards
Cell can be subdivided into three parts
Plasma (membrane), cytoplasm, nucleus
Cholesterol in the plasma membrane function
Controls fluidity of membrane on both sides
____ serves to stabilize the membrane and maintain optimal membrane fluidity
Cholesterol
The lipid bilayer is always permeable to what
Small, nonpolar, uncharged molecules. EX: 02, CO2, most steroids.
How are macromolecules only able to pass the plasma membrane?
Vesicular transport
The charge difference between a concentration gradient and an electrical gradient
Membrane potential
A concentration gradient, and an electrical gradient together is
Electrochemical gradient
Simple diffusion is influenced by
Steepness of the concentration gradient (the greater the difference in concentration the higher the rate of diffusion), temperature (higher temp equals faster), mass (smaller is faster), surface area (large the surface area, the faster diffusion rate), diffusion distance (shorter is better)
Water travels from
A higher concentration of solutes , which is a low concentration of water. Water follows sodium.
Symporters
Move two substances in the same direction
Antiporters
Move two substances in different directions
Phagocytosis
A form of endocytosis in white blood cells
What is cellular drinking and cellular eating?
Pinocytosis and phagocytosis
Transcytosis.
A combination of endocytosis and exocytosis used to move substances from one side of a self across it, and out of the other side. Ex: intestines
Centrosome
 Growth of the mitotic spindle and microtubule formation, pulling DNA into mitosis
Cilia and flagella
Cilia: move fluids over cells surface; flagella: move the entire cell (only in sperm)
Peroxisome
Containing oxidases, (oxidative enzyme) and catalase. Detoxifies, hydrogen peroxide and associated free radicals (antioxidants)
Proteasome
Degrades, unneeded, damaged, or faulty proteins by cutting them up into small peptides
Microvilli
Increase surface area for absorption of nutrients
Microfilaments
Made of myosin and actin, (help generate movement, muscle contraction, cell division, cell local motion) and provide mechanical support to inside the cell
Intermediate filaments
Protect cell from mechanical stress, and help organize cells organelles, cell attachment
Microtubules
Tubulin, cell shape, movement of organelles, chromosomal movement, make up cilia and flagella
Autophagy vs Autolysis
Autophagy usually refers to an ordered and purposeful digestion of cellular components. It’s basically the way a cell can deal with unused or poorly folded proteins. This is a normal cellular process. Autolysis on the other hand occurs when digestive enzymes leak out of lysosomes and start destroying the cell.
Transcription takes place in
The nucleus
Translation takes place in
The cytoplasm
Linking amino acids to form final chain
Translation
Cell cycle
Somatic cells duplicate their DNA and divide into two cells
Differentiation
When embryonic stem cells develop into specific body system cells
Telomeres
Are found at the tips of chromosomes and protect them from erosion and from sticking together (proteins)
