Human Anatomy & Physiology Chapter 3 Marieb
cells - (correct Answer) - structural units of all living things
cell theory - (correct Answer) - 1. cell is basic structural and functional unit of living organisms 2. activity
or organism depends on individual and collective activities of cells 3. biochemical activities are dictated
by shapes or forms and by the relative number of their specific subcellular structures 4. continuity of life
from one generation to the next has cellular basis
Cells are made of what 4 elements predominantly? - (correct Answer) - carbon, hydrogen, nitrogen,
oxygen
Three main parts of all cell - (correct Answer) - plasma membrane, cytoplasm with organelles, nucleus
general cell structure - (correct Answer) -
plasma membrane/ cell membrane - (correct Answer) - separates the intracellular from the extracellular
fluid (ECF)
fluid mosaic model - (correct Answer) - plasma cell is composed of bilayer of lipid molecules with protein
molecules and the proteins are floating in the fluid lipid bilayer
What is the lipid bilayer made from? - (correct Answer) - phospholipids, glycolipids, cholesterol, areas
called lipid rafts
phospholipids - (correct Answer) - a charged polar head that is hydrophilic, and a neutral charged
nonpolar tail made of two fatty acid chains. polar heads are attracted to water (the main constituent of
the intracellular and extracellular fluids) and lie on the inner and outer surfaces of the membrane, and
the hydrophobic nonpolar tails line up in the center of the membrane. since the phospholipids are
unsaturated for the most part, it causes more space between them and increase the fluidity
glycolipids - (correct Answer) - lipids with attached sugar groups. 5% of the membrane total. Their sugar
groups are like phospholipids and make the end of the molecule polar and the tails are nonpolar
cholesterol - (correct Answer) - 20% of membrane is cholesterol, and it has a polar region (hydroxyl
group -OH) and a non polar region (fused hydrocarbon ring system) that stabilizes the membrane and
decreases the mobility and fluidity of the membrane (more rigid)
Integral proteins - (correct Answer) - firmly inserted into the lipid bilayer, some protrude from one
membrane face only, but most are transmembrane proteins that span the entire membrane and stick
out on both sides of membrane, and have hydrophobic and hydrophilic regions. Involved in transport
lipid rafts - (correct Answer) - 20% of membrane, assembly of saturated phospholipids, unique lipids
called phingolipids, and cholesterol. lipid rafts are more stable and less fluid than the rest of the
membrane and typically concentrating platforms for certain receptor molecules and protein molecules
needed for cell signaling and membrane invagination
glycocalyx - (correct Answer) - sugary sticky carb-rich area that covers the cell surface which is enriched
by secretions from the glycolipids and glycoproteins. different cells have different patterns of sugar in its
glycolax, and the glycolax has specific biological markers by which approaching cells recognize each other
, (e.g. sperm can recognize ovum, immune system can recognize bacteria)
Functions of membrane proteins - (correct Answer) - transport, receptors for signal transduction,
attachment to cytoskeleton and extracellular matrix, enzymatic activity, intercellular joining, cell to cell
recognition
Functions of membrane proteins: transport - (correct Answer) - allows some solutes to go through, can
hydrolize ATP to pump substances across membrane
Functions of membrane proteins: receptors for signal transduction - (correct Answer) - membrane
protein exposed to the outside of the cell may have binding site that fits shape of chemical hormone,
and when bound it causes the shape to change and triggers a cascade of chemical reactions
Functions of membrane proteins: attachment to cytoskeleton and extracellular matrix - (correct Answer)
- anchors elements of the cytoskeleton and maintains cell shape, and may even bind adjacent cells
together
Functions of membrane proteins: enzymatic activity - (correct Answer) - a membrane protein may be an
enzyme with its active site exposed to substances in the adjacent solution, a team of several enzymes in
a membrane may catalyze steps of a metabolic pathway
functions of membrane proteins: intercellular joining - (correct Answer) - membrane proteins of adjacent
cells can get hooked together via various intercellular junctions, and some membrane proteins called cell
adhesion molecules or CAMS provide binding sites that guide cell migration
functions of membrane proteins: cell to cell recognition - (correct Answer) - some glycoproteins (proteins
bonded to short chains or sugars) can serve as tags that are recognized by other cells
What are 3 factors that bind cells together - (correct Answer) - glycoproteins in the glycocalyx act as an
adhesive, wavy contours of the membranes of adjacent cells fit together, special cell junctions form
(most important factor)
tight junction - (correct Answer) - integral protein molecules of adjacent cells fuse that forms an
impermeable membrane and that prevents molecules from passing through space e.g. tight junctions
between epithelial cells in digestive tract keep the enzymes from intestine from getting into
bloodstream. Some allow certain ions to pass despite impermeability.
desmosomes - (correct Answer) - Anchoring junctions. There is thick area called a plaque on the external
plasma membrane. Thin protein filaments that extend from the plaques velcro together in between the
cell faces. Intermediate filaments (keratin) extend from the cytoplasmic plaque across the cell width to
anchor the plaque on the cells opposite side. It distributes tension by having more connections and
reduces chances of tearing. Can be found in tissues subjected to mechanical stress, such as skin and
heart muscle
gap junctions (also known as nexus) - (correct Answer) - the adjacent plasma membranes are very close,
and are connected by short hollow cylinders called connexons composed of transmembrane proteins.
Ions, simple sugars, and other small molecules can pass through these water filled channels. Typically
found in smooth muscle and heart muscle and ion passage from cell to cell synchronizes electrical
activity and contraction
cells - (correct Answer) - structural units of all living things
cell theory - (correct Answer) - 1. cell is basic structural and functional unit of living organisms 2. activity
or organism depends on individual and collective activities of cells 3. biochemical activities are dictated
by shapes or forms and by the relative number of their specific subcellular structures 4. continuity of life
from one generation to the next has cellular basis
Cells are made of what 4 elements predominantly? - (correct Answer) - carbon, hydrogen, nitrogen,
oxygen
Three main parts of all cell - (correct Answer) - plasma membrane, cytoplasm with organelles, nucleus
general cell structure - (correct Answer) -
plasma membrane/ cell membrane - (correct Answer) - separates the intracellular from the extracellular
fluid (ECF)
fluid mosaic model - (correct Answer) - plasma cell is composed of bilayer of lipid molecules with protein
molecules and the proteins are floating in the fluid lipid bilayer
What is the lipid bilayer made from? - (correct Answer) - phospholipids, glycolipids, cholesterol, areas
called lipid rafts
phospholipids - (correct Answer) - a charged polar head that is hydrophilic, and a neutral charged
nonpolar tail made of two fatty acid chains. polar heads are attracted to water (the main constituent of
the intracellular and extracellular fluids) and lie on the inner and outer surfaces of the membrane, and
the hydrophobic nonpolar tails line up in the center of the membrane. since the phospholipids are
unsaturated for the most part, it causes more space between them and increase the fluidity
glycolipids - (correct Answer) - lipids with attached sugar groups. 5% of the membrane total. Their sugar
groups are like phospholipids and make the end of the molecule polar and the tails are nonpolar
cholesterol - (correct Answer) - 20% of membrane is cholesterol, and it has a polar region (hydroxyl
group -OH) and a non polar region (fused hydrocarbon ring system) that stabilizes the membrane and
decreases the mobility and fluidity of the membrane (more rigid)
Integral proteins - (correct Answer) - firmly inserted into the lipid bilayer, some protrude from one
membrane face only, but most are transmembrane proteins that span the entire membrane and stick
out on both sides of membrane, and have hydrophobic and hydrophilic regions. Involved in transport
lipid rafts - (correct Answer) - 20% of membrane, assembly of saturated phospholipids, unique lipids
called phingolipids, and cholesterol. lipid rafts are more stable and less fluid than the rest of the
membrane and typically concentrating platforms for certain receptor molecules and protein molecules
needed for cell signaling and membrane invagination
glycocalyx - (correct Answer) - sugary sticky carb-rich area that covers the cell surface which is enriched
by secretions from the glycolipids and glycoproteins. different cells have different patterns of sugar in its
glycolax, and the glycolax has specific biological markers by which approaching cells recognize each other
, (e.g. sperm can recognize ovum, immune system can recognize bacteria)
Functions of membrane proteins - (correct Answer) - transport, receptors for signal transduction,
attachment to cytoskeleton and extracellular matrix, enzymatic activity, intercellular joining, cell to cell
recognition
Functions of membrane proteins: transport - (correct Answer) - allows some solutes to go through, can
hydrolize ATP to pump substances across membrane
Functions of membrane proteins: receptors for signal transduction - (correct Answer) - membrane
protein exposed to the outside of the cell may have binding site that fits shape of chemical hormone,
and when bound it causes the shape to change and triggers a cascade of chemical reactions
Functions of membrane proteins: attachment to cytoskeleton and extracellular matrix - (correct Answer)
- anchors elements of the cytoskeleton and maintains cell shape, and may even bind adjacent cells
together
Functions of membrane proteins: enzymatic activity - (correct Answer) - a membrane protein may be an
enzyme with its active site exposed to substances in the adjacent solution, a team of several enzymes in
a membrane may catalyze steps of a metabolic pathway
functions of membrane proteins: intercellular joining - (correct Answer) - membrane proteins of adjacent
cells can get hooked together via various intercellular junctions, and some membrane proteins called cell
adhesion molecules or CAMS provide binding sites that guide cell migration
functions of membrane proteins: cell to cell recognition - (correct Answer) - some glycoproteins (proteins
bonded to short chains or sugars) can serve as tags that are recognized by other cells
What are 3 factors that bind cells together - (correct Answer) - glycoproteins in the glycocalyx act as an
adhesive, wavy contours of the membranes of adjacent cells fit together, special cell junctions form
(most important factor)
tight junction - (correct Answer) - integral protein molecules of adjacent cells fuse that forms an
impermeable membrane and that prevents molecules from passing through space e.g. tight junctions
between epithelial cells in digestive tract keep the enzymes from intestine from getting into
bloodstream. Some allow certain ions to pass despite impermeability.
desmosomes - (correct Answer) - Anchoring junctions. There is thick area called a plaque on the external
plasma membrane. Thin protein filaments that extend from the plaques velcro together in between the
cell faces. Intermediate filaments (keratin) extend from the cytoplasmic plaque across the cell width to
anchor the plaque on the cells opposite side. It distributes tension by having more connections and
reduces chances of tearing. Can be found in tissues subjected to mechanical stress, such as skin and
heart muscle
gap junctions (also known as nexus) - (correct Answer) - the adjacent plasma membranes are very close,
and are connected by short hollow cylinders called connexons composed of transmembrane proteins.
Ions, simple sugars, and other small molecules can pass through these water filled channels. Typically
found in smooth muscle and heart muscle and ion passage from cell to cell synchronizes electrical
activity and contraction
