Anatomy and Physiology Chapter 3 Cell Biology

• Forms the outer boundary of the cell
• The fluid-mosaic model, lipids, proteins and some sugars

• protects the cell
• separation of intracellular vs. extracellular materials
• is semipermeable, selectively permeable

the combination of carbohydrates and lipids (glycolipids) and proteins (glycoproteins) on outer surface of the plasma membrane

• polar heads facing the interior and exterior of the cell (hydrophilic)
• nonpolar tails (the fatty acids) facing each other on the interior of the membrane (hydrophobic)

• major lipid of plasma membrane
• interspersed among the phospholipids

• distribution of molecules within the membrane
• the phospholipids reassembled if membrane is damaged

• extend deeply into membrane
• functions as markers, attachment sites, channels, receptors, enzymes, or carriers

• attached to either the inner or outer surfaces of the lipid bilayer
• functions as markers, attachment sites, channels, receptors, enzymes, or carriers

allow cells to identify one another or other molecules

intergral proteins that allow cells to attach to other cells or extracellular molecules

attach cells to other cells

attach cells to extracellular molecule

• channel proteins
• carrier proteins

are one or more integral membrane proteins arranged so that they form a tiny channel through the plasma membrane

• have specific binding sites
• could be- uniporters, symporters, antiporters

move one particle

move two particles in the same direction

move two particles in opposite directions

act to catalyze reactions at outer/inner surface of plasma membrane

simple/passive or active means

• movement from high to low
• diffusion
• osmosis
• facilitated diffusion

• low to high concentration
• require energy (ATP)
• requires carrier protein
• rate of transport depends on amount of ATP

movement of solutes from area of higher concentration to lower concentration in solution

• diffusion of water(solvent) across a selectively permeable membrane
• water moves from an area of low concentration of solute to an area of high concentration of solute

• cell neither shrinks nor swells
• concentration of solutes in solution equal to that inside the cell

• cell shrinks (crenation)
• solution having high solute concentration, water move out of the cell by osmosis

• cell swells (lysis)
• solution having low solute concentration, water enters the cell by osmosis

involve carrier proteins or channel proteins

for a single type of molecule

rate of transport limited to number of the available carrier proteins

• molecules from high to low concentration and require carrier or channel proteins
• move large water soluble molecules or electrically charged molecules across the plasma membrane

• internalization of substances by formation of vesicles
• 3 types- phagocytosis, pinocytosis, receptor-mediated endocytosis

cell eating

cell drinking

• receptor molecules on cell surface bind to molecules to be taken into the cell
• the receptor and the bound molecules are taken into the cell as a vesicle begins to form
• the vesicle fuses and separates from the plasma membrane

• a secretory vesicle moves towards the plasma membrane
• the secretory vesicle fuses with the plasma membrane
• the secretory vesicle's contents are released into the extracellular fluid

• cellular materials outside nucleus but inside plasma membrane
• composed of 1/2 cytosol and cell organelles

the infrastructure of the cell made of fibrous proteins, supports the cell and holds the nucleus and other organelles in place, movements and changes in cell shape

• hollow tubes made of protein units called tubulin
• are involved in cell division and in transport of intracellular materials

• are small fibrils that form bundles, sheets or networks in cytoplasm
• provide structure to the cytoplasm

are protein fibers that provide mechanical strength to cells

aggregates of chemical either produced or taken in by the cell

• the control center of the cell
• consists of nuclear envelope, nucleolus, and chromatin or chromosome

• porous double membrane
• separates nucleoplasm from cytoplasm

• composed RNA and proteins
• site of ribosome production

stores information for synthesis of proteins

• Site of protein synthesis
• composed of a large subunit and a small subunit
• types= free and fixed/attached

• a network of membranous tubules within cytoplasm of a eukaryotic cell continuous with the nuclear membrane
• consists of broad flattened interconnecting sacs and tubules
• the interior spaces of those sacs and tubules is called cisternae and are isolated from the rest of the cytoplasm

• has attached ribosomes
• proteins production and modification

• no attached ribosomes
• manufactures lipids
• lipids metabolism

Composed of Flattened membrane sac stacked on each other

• modification, packaging, distribution of protein and lipid for secretion or internal use
• (the UPS Store)

• composed of microtubules two rod-like centrioles
• produce cilia, flagella and mitotic fibers to move the chromosomes during cell division

• enzyme-containing sacs
• break down organic molecules fatty acids and amino acids

• membrane bound vesicles that form at the golgi apparatus
• enzyme containing sacs (garbage disposal)
• digest worn out cell parts or unwanted substances

• a vesicle forms around material outside the cell
• the vesicle is pinched off from the plasma membrane and becomes a separate vesicle inside the cell
• a lysosome is pinched off the golgi apparatus
• the lysosome fuses with the vesicle
• the enzymes from the lysosomes mix with the material in the vesicles, and the enzymes digest the material

• located in the centrosome found near the nucleus
• center of microtubules organizing center
• before cell division centrioles divide, move to ends of cell and organize spindle fibers

• power house of the cell- cell generator
• convert chemical energy to ATP
• double membranes- Cristae and matrix
• contains DNA that codes for some of the mitochondrial protein enzymes

• one of mitochondrias membrane
• infoldings of inner membrane

substance located in space formed by inner membrane

• short appendages projecting from cell surfaces
• for movement and protection

• similar to cilia but longer and thicker
• usually only one per cell
• for movement
• ex-sperm cell

• glycolysis=2 ATP in cytosol
• Citric Acid Cycle and electron transport=26/28 ATP in matrix of mitochondria

RNA synthesis(requires energy) in the nucleus, DNA code is copied to mRNA

protein synthesis occur in the cytoplasm, on the ribosomes

2 strands of DNA molecule separate; new complementary strand is added using separate piece as a template

• interphase (G1, S, G2 phases)
• Mitosis
• Cytokinesis

cell carries out regular metabolic activities (G1) cell increases in size and doubles cell components and DNA (S phase) and the cell prepares to divide (G2)

the DNA is replicated (new DNA is synthesized)

the division of a cell's nucleus into two new nuclei each containing the same amount and type of DNA as original nucleus

• chromatin condense to form mitotic chromosomes each consists of two chromatids
• the centrioles move to the opposite ends of the cell and the nucleolus and nuclear envelope disappear

the chromosomes align near the center of the cell in association with the spindle fibers

chromatids separate and each chromatid is then referred to as a chromosome

• nuclear envelopes form around each set of chromosomes to form two separate nuclei
• the chromosomes begin to uncoil

• cytoplasmic division, separate process from mitosis
• begins in anaphase and continues through telophase first sign is the formation of a cleavage furrow

an indentation of the plasma membrane that forms midway between centrioles

• cell division for gametes production interphase followed by two cell divisions
• results in four haploid gametes
• containing 1/2 of the chromosomes
• genetically not identical
• ovum and sperm unite to form a zygote