Chapter 1 Plant and Cell Architecture
Figures to know
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1.2.
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1.3.
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1.5.
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1.6.
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1.11.
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1.23.
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1.25.
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1.27.
Concepts to know.
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Describe unique features of plant life cycles. Or plant life processes.
▪ Plants alternate between two distinct multicellular generations to complete their life cycle
– One generation has diploid cells, cells with two copies of each chromosome, 2N - sporophyte
– One generation has haploid cells, cells with only one copy of each chromosome, 1N gametophyte
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▪ Monoecious – both male and female parts
▪ Diecious – individual sexes per plant
Be able to describe the plant life cycle that alternates between diploid and haploid generations.
▪ One generation has diploid cells, cells with two copies of each chromosome, 2N – sporophyte
▪ One generation has haploid cells, cells with only one copy of each chromosome, 1N gametophyte
Describe the fundamental properties of plant structures, including cell walls.
▪ The vegetative body consists of three organs:
1. Stem - grows upward and supports the above ground part of the plant
2. Root - anchors the plant and absorbs nutrients and water, and grows down below the
ground
3. Leaves - primary function is photosynthesis, grow laterally from the stems at the node
▪ 2 types of cell wall
1. Primary cell walls – Typically <1 micrometer thin – new growth
2. Secondary wall - Thicker and stronger than primary wall
a. Deposited on the inner surface of the primary wall after most cells’ enlargements
has ended
b. Owe their strength and toughness to lignin, a brittle material
Distinguish the structural and functional difference of plant tissue types.
1. Dermal tissue - forms the outer protective layer of the plant, epidermis in the primary plant
body
2. Ground tissue - fills out the 3D bulk of the plant and includes the pith and cortex of primary
stems and roots and the mesophyll in leaves pith, cortex, stem, roots, and mesophyll
3. Vascular tissue – consists of two types of tissues: xylem and phloem, each of the which consists
of conducting cells, generalized parenchyma cells and thick-walled fibers
Be able to explain the biochemical structure and behavior of plant cell membranes and associated
proteins.
▪ The endomembrane system and peroxisomes:
a. Except for some peroxisomes components of the endomembrane system are not formed
by semiautonomous processes
b. The endomembrane system plays a central role in secretory processes, cell signaling,
specialized metabolite and hormone production, membrane recycling, the cell cycle and
cell expansion.
cell secretion, signaling, metabolite, hormone, cycle, and expansion
2. Semiautonomous (independently dividing) organelles of endosymbiotic origin:
a. Plastids and mitochondria, these organelles function in energy metabolism and storage,
and they synthesize a wide range of metabolites in the biosynthesis of all cell
components. oxygen and glucose
▪ Biological Membranes:
1. Integral membrane proteins- proteins that are embedded in the lipid bilayer of a
membrane via at least one transmembrane domain.
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2. Peripheral membrane proteins- proteins that are bound to the membrane surface by
noncovalent bonds, such as ionic bonds, or hydrogen bonds.
3. Anchored proteins – proteins that are bound to the membrane surface via lipid
molecules, to which they are covalently attached.
4. Glycosylphosphatidylinositol anchor – in plants, a phosphoglyceride protein
modification that anchors proteins to ordered plasma membrane domains.
Define the elements of the cytoskeleton and explain their biological activity.
▪ Microtubules:
a. Are polarized hollow cylinders with an outer diameter of 25 nm; composed of polymers
of the protein tubulin
b. a component of the cell cytoskeleton and the mitotic spindles, and a player in the
orientation of cellulose microfibrils in the cell wall. Made of tubulin
2. Microfilaments:
a. Are a solid with a diameter of 7nm; composed of the monomeric form of the protein
Actin, or globular actin (G-actin).
b. A component of the cell cytoskeleton made of an Actin; it is involved in organelle
motility within cells.
Describe the role of the endomembrane system components in the left cells
▪ Exocytosis - the process that allows forward trafficking of biosynthetic cargo and membranes
from the site of synthesis, the ER and the Golgi apparatus
▪ Endocytosis - is the opposite (retrograde) process of exocytosis. The plasma membrane forms
invaginations that allow the cell to incorporate internalized plasma membrane and extracellular
material into the cell or recycle those components back to the plasma membrane
▪ Autophagy - a catabolic mechanism that conveys cellular macromolecules and organelles via
autophagosomes to lytic vacuoles where they are degraded and recycled
Differentiate between the two main types of semi-autonomous organelles in plants
▪ Mitochondria - Specialize in cellular respiration to produce ATP by breaking down glucose and
oxygen
▪ Matrix - enzymes, ribosomes, and circular DNA
▪ Main location of the enzymes involved in oxidative phosphorylation and energy
metabolism
▪ Divided by fission
▪ Plastids - Specialize in photosynthesis to produce glucose and oxygen using light energy
▪ Specialize in photosynthesis to produce glucose and oxygen using light energy
▪ In addition to their inner and outer envelope membranes, chloroplasts possess a third
system of membranes called thylakoids
▪ The fluid compartment surrounding the thylakoids, called the stroma, is analogous to the
matrix of the mitochondrion
Distinguish between the different molecular and cellular processes into their corresponding phase in the
cell cycle.
▪ Stages of mitosis:
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
5. Cytokinesis
6. Cell plate
Chapter 2 Water and Plant Cells
Vocabulary
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Adhesion - the attraction of water to a solid phase such as a cell wall or glass surface, due primarily to
the formation of hydrogen bonds
Aquaporins - facilitate the movement of water across membranes
Capillarity - the movement of water for small distances up a glass capillary tube or within the cell wall,
due to water’s cohesion, adhesion, and surface tension
Cavitation - the collapse of tension in a column of water resulting from the formation and expansion of
tiny gas bubbles
Chemical potential - quantitative expression of the free energy associated with a substance
Cohesion - mutual attraction between water molecules due to extensive hydrogen bonding
Contact angle - quantitative measure of the degree to which a water molecule is attracted to a solid phase
versus to itself
Diffusion - the net movement of substances form regions of higher to lower concentration
Electronegative - The tendency of an atom in a molecule to attract the shared pair of electrons towards
itself
Gravitational potential - depends on the height (h) of the water above the reference-state water, the
density of water and the acceleration due to gravity
Halophytes - plants that are native to saline soils and complete their life cycles in that environment
Hydraulic conductivity - the ease with which a fluid (usually water) can move through the pore space, or
fracture network
Hydrogen bonds - an attractive dipole-dipole interaction between a partially positive charged hydrogen
atom in one molecule and a partially negative charged atom in the same or different molecule
Hydrostatic pressure - the pressure generated by compression of water into a confined space
Latent heat of vaporization - the energy needed to separate molecules form the liquid phase and move
them into the gas phase at Constant temperature
Matrix potential - adhesion to structures such as cell walls, membranes, and soil particles
Osmosis - the net movement of a solvent across a selectively permeable barrier from a region of lower to
higher solute concentration
Osmotic potential - effect that solutes have on ψ
Polar – molecule with uneven distribution of electrical charge
Pressure potential - effect that pressure has on ψ
Selectively permeable - the ability of a membrane to allow certain molecules or ions to pass through it
while inhibiting the passage of others
Solute potential - the effect of dissolves solutes on water potential
Specific heat capacity - The Ratio of the heat capacity of a substance to the heat capacity of a reference
substance
Surface tension - The energy required to increase the surface area of a gas-liquid interface
Tensile strength - the maximum force per unit area that a continuous column of water can withstand
before breaking
Tension - Negative hydrostatic pressures frequently develop in xylem conduits
Transpiration - the evaporation of water from the surface of leaves and stems
Turgor pressure - Positive hydrostatic pressure in cells
Water potential - The measure of the relative tendency of water to move from one area to another
Figures to know.
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2.3.
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2.7.
Concepts to know:
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Understand the role of water as a limiting resource for natural and agricultural ecosystems
▪ underscores the need for sustainable management practices to ensure the well-being of both
natural and agricultural ecosystems
▪ most abundant and at the same time the most limiting for productivity
Describe the physical and chemical properties that make water an excellent solvent.
▪ medium for the movement of molecules within and between cells and greatly influences the
structure of proteins, nucleic acids, polysaccharides, and other cell constituents
Explain the importance of diffusion and osmosis in transport over short cellular distances.
▪ Diffusion is the movement of molecules or ions from an area of higher concentration to an area
of lower concentration
▪ Osmosis is the movement of water molecules across a selectively permeable membrane from an
area of lower solute concentration to an area of higher solute concentration
▪ Fundamental processes that enable cells to maintain their internal environment, support
metabolic activities, and communicate with their surroundings
Know the water potential formula and describe how each of the three main factors contribute to it.
▪ ψ = ψπ + ψp + ψm
▪ ψp = pressure potential: effect that pressure has on ψ– If water is under pressure, both pressure
potential and water potential increase.
▪ ψπ = osmotic potential: effect that solutes have on ψ– Adding solutes decreases water’s free
energy, so ψπ is always negative.
▪ ψm = matric potential: adhesion to structures such as cell walls, membranes, and soil particles
Describe the movement of water at the cellular level under different values of water potential. Explain
the different physiological functions of cell wall and cell membrane with respect to water movement and
plants.
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The movement of water at the cellular level is crucial for maintaining cellular functions and
overall plant health. The cell wall and cell membrane each play vital roles in regulating this
movement and ensuring proper physiological responses
Describe how water status affects many other functions in plants.
▪ Water status is a fundamental factor that affects almost every aspect of plant life. Proper water
management is crucial for ensuring optimal growth, productivity, and resilience in plants
Chapter 3 Water Balance of Plants
Vocabulary.
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Casparian strip - band within the radial cell walls of the endodermis that is impregnated with lignin
Cellulose microfibrils - elongated structures in plant cell walls composed of cellulose chains arranged in
a highly organized, crystalline fashion. Provide exceptional mechanical strength, contributing to the
stiffness and solidity of plant tissues
Chloroplast envelope - a double membrane system surrounding the chloroplast
Difference in water vapor concentration - between leaf and air are responsible for the diffusion of water
vapor from the leaf to the air
Diffusional Resistance - the restriction posed by the boundary layer and the stomata to the free diffusion
of gases from and into the leaf
Guard cells - surround the stomatal pore. Have specific shapes for specific jobs and portions of the walls
are substantially thick for protection.
Leaf stomatal resistance - The resistance associated with the diffusion through stomatal pores - The
resistance of CO2 diffusion imposed by the stomatal pores.
Lignin - highly branched phenolic polymer made-up of phenylpropanoid alcohols that is deposited in
secondary cell walls
Microfibrils - a small fibril in the cytoplasm or wall of a cell, visible only under an electron microscope,
and typically aggregated into coarser fibrils or structures
Osmotic potential - The effect of dissolved solutes on water potential, also called solute potential
Soil hydraulic conductivity - a measure of the ease with which water moves through soil
Stomatal complex - crucial structure in plant biology that plays a vital role in regulating gas exchange
and water loss. It consists of the stomata (tiny openings or pores) and the surrounding specialized cells,
mainly the guard cells and sometimes subsidiary cells
Subsidiary cells - pair of differentiated epidermal cells called subsidiary cells – help control stomatal
pore
Tracheids - elongated spindle shaped cells that are arranged in overlapping vertical files
Transpiration ratio - measures the relationship between water loss and carbon gain
Vessels - one of the two main types of xylem elements, the other being Tracheids. They play a crucial
role in the transport of water and dissolve minerals from the roots to the rest of the plant
Vessel elements - end walls that are partially or completely open, so they can be stacked end to end to
form a multicellular conduit called a vessel
Figures to know
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3.1.
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3.2.
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3.4.
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3.10.
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3.12
Concepts to know.
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Explain the forces involved in water movement through the soil.
▪ Gravity – responsible for the drainage of excess water from the soil, especially after heavy
rainfall or irrigation
▪ Osmotic potential – Water moves from areas of lower solute concentration to areas of higher
solute concentration
▪ Capillary action – helps in the upward movement of water from wetter to drier soil layers,
particularly in the absence of rainfall
▪ Matric potential – determines the availability of water to plants by holding water in the soil
pores
▪ Hydraulic conductivity – influenced by soil texture, structure, and moisture content. Soils with
high hydraulic conductivity, like sandy soils, allow water to move more freely compared to
clayey soils
Explain how water is absorbed by roots and how it reaches the Xylem.
▪ Contact between the surface of the root and the soil
▪ Root hairs are a filamentous outgrowths of root epidermal cells – expand area of root
▪ Water flows between soil particles from the epidermis to the endodermis of the root
Describe the role of xylem in water transport and the forces involved in water movement through these
cells.
▪ Contributes to root pressure in plant
▪ 99.5% of the water transport pathway through the plant is within the xylem
Explain how water moves from the leaf to the atmosphere and how the stomata regulate this process.
▪ When leaves open their stomata to obtain CO2 for photosynthesis, water vapor diffuses out of
the leaves causing water to evaporate from the surface of the mesophyll cell walls inside the
leaves - diffusion
Differentiate the mechanisms of water transport from the soil through the plant to the atmosphere
▪ 3 mechanisms of transport:
1. In the soil and the Xylem, liquid water moves by bulk flow in response to a pressure
gradient.
2. When liquid water is transported into and out of cells, the driving force is the water
potential difference across the plasma membrane.
3. In the vapor phase, water moves primarily by diffusion, at least until it reaches the
outside air, where convection, a form of bulk flow, becomes dominant.