Part 4: Organic Compounds 2 Flashcards
the study of cells
cytology
living organisms are made up of cells, they have basic structural/organizational system, and all cells come from pre-existing cells, simplest structure, physiological processes in body based on cellular activity
cell theory
the fluid between the nucleus, thought to be a gelatinous mixture of chemicals
cytoplasm
made of 75% phospholipids, 20% cholesterol, 5% glycolipids. defines the boundaries of the cell, governs the interactions with other cells, and controls passage of materials into and out of the cell
plasma membrane
system of protein microfilaments, intermediate filaments, and microtubules in a cell, serving in physical support, cellular movement, and the routing of molecules and organelles to their destinations
cytoskeleton
any structure within a cell that carries out one of its metabolic roles
organelles
AKA transmembrane protein. extends through a plasma membrane and contacts both the extracellular and intracellular fluid. hydrophilic on the outsides, hydrophobic on insides. Some float freely while others are attached to the cytoskeleton
integral protein
do not protrude into the phospholipid layer but adhere to either the outer or inner face of the membrane
peripheral protein
respond to chemical messengers
ligand-gated channel
respond to changes in electrical potential across the plasma membrane
voltage-gated channel
responds to physical stress on a cell, such as stretch and pressure
mechanically-gated channel
intracellular signaling that begins outside of the cell
second messenger
G-protein relays the signal to this membrane protein. It removes two phosphate groups from ATP and converts it to cyclic AMP (2nd messenger)
adenylate cyclase
the second messenger. activates cytoplasmic enzymes
cyclic AMP
cytoplasmic enzymes that add phosphate groups to other cellular enzymes
Kinase
the protein in which the receptor is linked to
G protein
composed of CHO moieties of glycoproteins and glycolipids. Its functions include:
Protection
Immunity to infection
Defense against cancer
Transplant compatibility
Cell Adhesion
Fertilization
Embryonic development
glycocalyx
extensions of the plasma membrane that serve primarily to increase a cell’s surface area
microvilli
hairlike processes. move mucus. have a power stroke and a recovery stroke
cilia
tail of sperm
flagella
cytoplasm filled extensions of the cell. continuously change in shape.
pseudopod
Explain why the relationship between cell volume and surface area is important.
The relationship between cell volume and surface area is important to the function of the cell. If a cell is too large, the amount of nutrients needed, the communication within the cell, and other metabolic processes will be much slower and could possibly lead to miscommunication.
Describe the structure of a plasma membrane.
The plasma membrane is a phospholipid bilayer with hydrophilic heads and hydrophobic tails. There are different types of proteins and channels throughout the membrane and on the inner and outer layers. Cholesterol is also found within the membrane, and glycolipids and CHO chains are found on the outside. Right beneath the membrane is the cytoskeleton.
Describe the different lipids in the membrane.
98% of the membrane molecules are lipids. 75% of them are phospholipids, 20% is cholesterol, and the final 5% are glycolipids
Distinguish between integral proteins and peripheral proteins.
Integral proteins go all the way through the plasma membrane while peripheral proteins sit on the outer and inner parts of the plasma membrane
Describe the functions of membrane proteins.
1)Receptors- accept chemical messages, typically specific for one particular message
2)Second Messenger System- involves transmembrane proteins and peripheral proteins
3)Enzymes- carry out the final stages of starch and protein digestion, help produce second messengers, break down hormones and other signals
4)Channel Proteins- allow water and hydrophilic solutes to move through the membrane
5)Carriers- bind to glucose, electrolytes, and other solutes and transfer them to the other side of the membrane
6)Cell-Identity Markers- identification tag
7) Cell-adhesion molecules- cells adhere to one another and to extracellular material
What is the glycocalyx?
The glycocalyx is a “fuzzy coat” that all animal cells have. It is chemically unique to everyone but identical twins. It acts like an identification tag that enables the body to distinguish its own healthy cells from transplanted tissues, invading organisms, and diseased cells
What are microvilli, cilia, and flagella?
surface extensions that aid in absorption, movement, and sensory processes.
