PLANT SCI 221 EXAM QUESTIONS AND
ANSWERS LATEST UPDATE
Prokaryotic vs. Eukaryotic
Pro and Euk= cell wall, Euk= only has ribosome
Why is larger cells at a disadvantage
Have a higher SA so it takes longer for nutrients, minerals, water, and for instruction
from the nucleus to reach across the whole cell.
Protoplasm
inside the cell wall, consist of all living components of the cell.
Plasma membrane
bounds the living components in, regulates movement of substances in and out of cell
(semi-permeable and can be selectively permeable), produces and assembles cellulose
for cell walls
Protiens in the Plasma membrane
Peripheral protein- not all the way in
Integral protein- Passes all the way through, Can cause a channel
Composition of plasma membrane
Phospholipid bilayer, consist of HydroPHILIC (lover) head and HydroPHOBIC (hater)
tail, because envirmoent and cytoplasm is watery (favours head). consist of a
UNSATURATED (bend) and SATURATED (straight) tails.
Cholesterol in phospholipids
stability in the bilayer and controls what passes through it
Cytoplasm
souplike fluid called cytosol (where organelles are dispersed)
Cytoplasm vs Protoplasm
Cyt= everything but no nucleus, Prot= everything (nucleus)
Cell wall
most abundant and diverse biological structure on earth, provides Food, Fuel, and
shelter/protection
Importance- cell shape, Control of expansion, Provides protection, regulates transport,
stores food
What is the cell wall made of
Structural carbohydrates (Cellulose, hemicellulose, and pectins) with Lignin.
Cellulose
Glucose monomers in long chains, In primary Cell wall
Hemicellulose
Holds cellulose fibrils together, In Primary cell wall
Pectin
Organic material that gives stiffness to fruit jellies, In the middle lamella and primary cell
wall
, Glycoproteins
proteins with sugar that associates with molecules
Middle Lamella
first produced when new cells are formed, shared by two adjacent cells
Secondary cell wall
Derived from primary cell walls by thickening and inclusion of lignin. Contains 40%-80%
more cellulose than primary walls. cells wall thicken as cell ages (5%-95%)
Secondary wall formation
Cellulose microfibrils become embedded with lignin and acts as steel rods in concrete
Cell types compared to wall thickness
cells that process and store food = Thin walls
Cells involved with support = Thick walls
Cell communication
- Plasmodesmata allow for substance to pass through primary wall
- Middle Lamellae and most cells are permeable and permit slower movement of water
and dissolved substance
Plasmodesmata
tiny strands of cytoplasm that extend between cells through tiny openings
Nucleus
DNA for growth and other activities
3 parts- Envelope (bound together by membranes), Pore (takes up 1/3 and permits
molecules in and out), Nucleolus (holds DNA)
Chromatin is found here which is used to create chromosomes
Endoplasmic Reticulum
outer membrane of nucleus (flat sacs and tubes), Main source for cellular
communication. Synthesizes membranes for other organelles by modifying proteins
which are modified by the dictyosomes
Rough vs smooth ER
Rough- has ribosomes, function for synthesize, secretion, and storage of proteins
Smooth- No ribosomes, only for secretion of lipids
Ribosome's
found floating and attached to membranes, made up of RNA and proteins which allow
them to start and cause protein synthesize
Dictyosome (post office)
Modifies CHO's from being attached to proteins that are synthesized and packaged in
the ER, assembles the polysaccharides then collects them in small vesicles which
migrate around plasma membrane
What does the vesicles secrete
Cell-wall polysaccharides
Floral nectars
Essential Oils
ANSWERS LATEST UPDATE
Prokaryotic vs. Eukaryotic
Pro and Euk= cell wall, Euk= only has ribosome
Why is larger cells at a disadvantage
Have a higher SA so it takes longer for nutrients, minerals, water, and for instruction
from the nucleus to reach across the whole cell.
Protoplasm
inside the cell wall, consist of all living components of the cell.
Plasma membrane
bounds the living components in, regulates movement of substances in and out of cell
(semi-permeable and can be selectively permeable), produces and assembles cellulose
for cell walls
Protiens in the Plasma membrane
Peripheral protein- not all the way in
Integral protein- Passes all the way through, Can cause a channel
Composition of plasma membrane
Phospholipid bilayer, consist of HydroPHILIC (lover) head and HydroPHOBIC (hater)
tail, because envirmoent and cytoplasm is watery (favours head). consist of a
UNSATURATED (bend) and SATURATED (straight) tails.
Cholesterol in phospholipids
stability in the bilayer and controls what passes through it
Cytoplasm
souplike fluid called cytosol (where organelles are dispersed)
Cytoplasm vs Protoplasm
Cyt= everything but no nucleus, Prot= everything (nucleus)
Cell wall
most abundant and diverse biological structure on earth, provides Food, Fuel, and
shelter/protection
Importance- cell shape, Control of expansion, Provides protection, regulates transport,
stores food
What is the cell wall made of
Structural carbohydrates (Cellulose, hemicellulose, and pectins) with Lignin.
Cellulose
Glucose monomers in long chains, In primary Cell wall
Hemicellulose
Holds cellulose fibrils together, In Primary cell wall
Pectin
Organic material that gives stiffness to fruit jellies, In the middle lamella and primary cell
wall
, Glycoproteins
proteins with sugar that associates with molecules
Middle Lamella
first produced when new cells are formed, shared by two adjacent cells
Secondary cell wall
Derived from primary cell walls by thickening and inclusion of lignin. Contains 40%-80%
more cellulose than primary walls. cells wall thicken as cell ages (5%-95%)
Secondary wall formation
Cellulose microfibrils become embedded with lignin and acts as steel rods in concrete
Cell types compared to wall thickness
cells that process and store food = Thin walls
Cells involved with support = Thick walls
Cell communication
- Plasmodesmata allow for substance to pass through primary wall
- Middle Lamellae and most cells are permeable and permit slower movement of water
and dissolved substance
Plasmodesmata
tiny strands of cytoplasm that extend between cells through tiny openings
Nucleus
DNA for growth and other activities
3 parts- Envelope (bound together by membranes), Pore (takes up 1/3 and permits
molecules in and out), Nucleolus (holds DNA)
Chromatin is found here which is used to create chromosomes
Endoplasmic Reticulum
outer membrane of nucleus (flat sacs and tubes), Main source for cellular
communication. Synthesizes membranes for other organelles by modifying proteins
which are modified by the dictyosomes
Rough vs smooth ER
Rough- has ribosomes, function for synthesize, secretion, and storage of proteins
Smooth- No ribosomes, only for secretion of lipids
Ribosome's
found floating and attached to membranes, made up of RNA and proteins which allow
them to start and cause protein synthesize
Dictyosome (post office)
Modifies CHO's from being attached to proteins that are synthesized and packaged in
the ER, assembles the polysaccharides then collects them in small vesicles which
migrate around plasma membrane
What does the vesicles secrete
Cell-wall polysaccharides
Floral nectars
Essential Oils
