Ch.3: Cells, The living units Flashcards
The building blocks of plants, and animals
Cells
A human cell has three main parts
plasma membrane
cytoplasm
nucleus
Separates two of the body fluid: intracellular fluid within cells and extracellular fluid outside cells
Plasma membrane
The three lipid layer that forms the basic “ fabric” of the membrane are
Phospholipids, glycolipids, cholestorol, and lipid rafts
Lipid Layer, that contains a polar head (hydrophillic), and nonpolar tail (hydrophobic). Parallel sheets, assemble close to one another. Important in determining local membrane structures and function. 70% of the cell membrane
Phospholipids
Lipid layer, with attached sugar groups “cell identity”, found on the outer plasma membrane surface. 5% of total cell membrane
Glycolipids
Lipid Layer , polar (hydroxl) and nonpolar (ring) , wedges between the phospholipid tail, stabilizes the membrane while decreasing mobility& fluidity of membrane 20% of cell membrane
Cholestorol
Make up about half of the plasma membrane by mass and are responsible for most of the specialized membrane functions
Membrane Protein
integral proteins main functions
form channels
carriers (revolving door)
receptors (signal transduction)
Peripheral protein are
network of filaments, enzymes, motor proteins (change shape), and link cells together
” sugar covering” enriched both by glycolipids and glycoproteins secreted by the cell, CELL RECOGNITION
Glycocalyx
homeostasis imbalance of the Glycocalyx can cause the cell to be
Cancerous, allows cells to keep dividing, allow to keep ahead of immune system recognition and avoid destruction
What are the three main cell junctions
tight junctions, desmosomes, gap junctions
An example of a tight junction would include
skin, lining of the digestive tract, blood-brain barrier, testis barrier
An example of desmosomes would include, and what does it prevent?
skin & heart muscle, uterus. prevent separation
An example of Gap junctions would include, and what does it do?
neurons, cardiac & smooth muscle, communication (connexons)
What are the two ways to move through the plasma membrane?
Active Transport & Passive Transport
Two main types of passive transport are
Diffusion and Filtration
Characteristics of simple diffusion
unassisted diffusion of lipid molecules
diffuse directly
gases,lipid soluble, alcohol, fat soluble vitamins
Characteristics of facilitated diffusion
assisted diffusion of lipid molecules
carrier channels
glucose water soluble
Define Osmosis
Diffusion of water molecules
Water Diffuses through
Aquaporins
What happens to the blood cell when put in a hypertonic solution?
The cell shrinks (crenation)
What happens to the blood cell when put in a hypotonic solution?
The cell expands (hemolysis)
What is a solution called when it has equal number of solutes and water molecules?
Isotonic (ex. I.V)
What is an active transport?
a cell that uses energy to transport solutes across the membrane
What are the 2 forms of active transport?
primary and secondary transport
Characteristics of primary active transport are
energy comes directly from hydrolysis of ATP (sodium and potassium pump)
Characteristics of secondary active transport are
recycled energy from primary active transport
symport system same direction
antiport system opposite direction
Fluids containing large particle macromolecules are transported by
Vesicular transport
Endocytosis is
moving substances into the cell
what are the 3 types of endocytosis
phagocytosis
pinocytosis
receptor mediated endocytosis
what is exocytosis, and what does it account for?
move substances out of the cell
it accounts for hormone secretion, neurotransmitter release, mucous secretion, ejection of waste
Apoptosis is
Process of control cellular suicide
Eliminate cells that are
stressed
no longer needed
injured
aged
Hyperplasia is
accelerated growth of cells and tissues (ex. Anemic)
Atrophy is
Decrease in size of an organ or body tissues (muscular dystrophy)
