FINAL OF FINALS Flashcards
perennials that create stiff structures above ground
Woody Plants
Types of woody plants
Trees
Shrubs
Vines
climb on other plants or on inanimate
structures like a fence or a wall
Vines
“backbone” for support
Wood
“skin” for protection
Bark
only part of the trunk that is alive
Cambial layer
transports water and mineral salts from roots to the other parts of the tree
Xylem
transports sucrose and amino acids between the leaves and other parts of the plant
Phloem
The old xylem becomes
wood
The old phloem becomes
the bark
an aggregate of untold number of small
units called cells.
Wood
It is an intercellular substance that separates wood cells
Middle lamella
In each cell, there is a wall enclosing a lumen which contains a vital plant substance called
Protoplasm
the living part of the cell, which comprises of different cellular organelles.
Protoplasm
It is a jelly-like, colorless, transparent, and viscous living substances present within the cell wall
Protoplasm
The substance present between the cell
membrane and the nucleus.
Cytoplasm
What does protoplasm contains?
cytoplasm and the nucleus.
What does cytoplasm contain?
cell organelles like Golgi bodies, endoplasmic reticulum, mitochondria, ribosomes, but no nucleus.
Jelly-like fluid containing water, proteins
and metabolic wastes.
Cytoplasm
What are the chemical composition of wood and their corresponding %?
Lignin 15-25
Hemicellulose 23-32
Cellulose 38-50
What is the purest form of cellulose known in nature?
Cotton
the polysaccharide fraction of the woody element comprising about 60-70%
Holocellulose
Man can digest starch (a polysaccharide) but not _______ which animals can
digest because of cellulose enzymes present in their guts or stomachs.
Cellulose
long chain of glucose units that polymerize into microfibrils.
Cellulose
matrix substance of the cell wall composed of two types of sugar molecules: xylans and glucomannans.
Hemicellulose
made of intractable material which acts as the cementing substance of wood
Lignin
deters insect and fungal attack and functions as a water barrier; a complex, 3- dimensional substance;
Lignin
the major chemical component of wood fibers; composed of long chains (10,000 + ) of glucose sugar molecules;
Cellulose
“coat” the cellulose chains and help the lignin bind to the cellulose; made up of sugars (glucose)
Hemicellulose
A newly formed wood cell is encased in a thin, membrane-like and pectin-rich wall called a
Primary wall
made up of microfibrils that are dispersed in a loose, irregular interwoven pattern
Primary wall
angle of orientation becomes successively smaller from the inner to the outer parts
Primary wall
intercellular material extending between the cell walls of adjacent wood cells
True middle lamella
refers to the true middle lamella and the primary cell walls of two adjacent wood
cells
Compound middle lamella
non-structural constituents of wood composed of low molecular weight organic compounds
EXTRACTIVES
Composed only 10% in trees but are diverse and extracted through solvents
EXTRACTIVES
Most wood extractives are ______ and only a little part is water-soluble
lipophilic
3 main groups of extractives
- Aliphatic compounds
- Terpenes
- Phenolic compounds
What is the importance of learning the composition of wood?
It will let us know how we can utilize wood effectively and efficiently.
the first clearly visible layer of the cell wall and is located between the plasma membrane and the middle lamella or, in some cells, between the secondary wall and the middle lamella.
Primary cell wall
Plant cells stop growing when the primary cell wall become ______, which may be due to a change in their composition.
Rigid
plant cells create channels that cross the cell walls and allow direct communication between adjacent cytoplasms these channels are called
plasmodesmata.
Plasmodesmata are usually concentrated in.
primary pit fields
T/F. Cells with primary cell wall are usually metabolically active and the cells that develop secondary cell walls usually
have thin primary cell wall.
TRUE
It is a linear polysaccharide formed by glucose monomers linked by β(1-4) bonds. The formula is (C6H10O5)n, where n can be greater to 500 per polysaccharide chain.
Cellulose
T/F. The strength of cellulose fibers is similar to that of steel and the bonds between cellulose molecules by hydrogen bonds make the cellulose microfibrills have crystalline properties in some regions, while the rest acquires paracrystalline properties.
True
It is synthetized in the Golgi apparatus and is transported to the plasma membrane in vesicles, where it is released by exocytosis.
Hemicellulose
the most frequent molecule of hemicellulose.
Xyloglucan
they coat the cellulose microfibrils, helping to the cohesion to form
cellulose fibers.
Synthesized hemicellulose molecules
It form a very diverse group of acidic polysaccharides synthetized in the Golgi
apparatus and secreted into the cell wall.
Pectins
They seem the main ones responsible for the formation of pores that allow the diffusion of small molecules through the primary wall.
Pectins
They are usually rich in proline, hydroxyproline and glycine, amino acids that are found in much repeated sequences found in the cell wall.
Glycoproteins
a substance that is deposited between the plasma membrane and the cell wall; then, it cannot be considered srictly as a component of the primary cell wall.
Callose
It also appears in other places with less clear functions, such as in the pollen tubes or in the cell plate during
cytokinesis.
Callose
This layer, which can be very thick, prevents the loss of water and protects against pathogens.
Cuticle
cells that have the mission of support and those conductors that are part of the xylem develop an additional wall layer called
Secondary cell wall
Once the cell wall is synthetized, the cells die by _______.
Opoptosis
T/F. The proportion of cellulose in the secondary wall is lower than that in the primary wall and it also has hemicellulose in lower proportion.
False, cellulose in 2ndary cell wall is higher
What is the typical substance of the secondary cell wall?
Lignin
They are the interruptions or channels in the entire cell
Pits
What membrane separates the two aligned pits of neighboring cells; this membrane is formed by the middle lamella and the primary walls of the two cells.
Pit membrane
natural products extraneous to a lignocellulose cell wall. They are present within a cell wall but are not chemically attached to it.
Wood extractives
What are the functions of extractives?
to conserve energy in the tree metabolism, and protect against microbial attacks such as fungi, and/or insects.
Effects of extractives on wood
Color
Smell
Hygroscopy
Natural durability
Dimensional stability
acoustic properties
synthesized by the epithelial cells (specialized tissue of the parenchyma), which line the resin canals. They’re responsible for the aromas, flavors, and even colors associated with various types of vegetation.
Terpenes
It protects plants and wood against pathogens such as molds, fungi, and bacteria and can attract pollinating insects or repel herbivores and serves as as resistance to diseases and attacks by microorganisms, and creation
of odor (nerolidol, farnesol, cedrol).
Terpenes
also referred to isoprenoids, are a vast group of naturally occurring compounds with medicinal potencies. (anti cancer compounds)
Terpenoids
They allow the use of hydrocarbons as fuel, such as methane in Bunsen burners and as liquefied natural gas (LNG), and acetylene in welding.
Aliphatic compounds
also known as non-aromatic compounds and are flammable.
Aliphatic compounds
compounds play a preventive role against cancer and heart problems. They also have a protective effect against ultraviolet rays, pathogens, herbivores, and lipids protect against oxidation of the cell membrane.
Aromatic Phenolic Compounds
What is the best-known phenolic acid?
Salicylic acid
found in the knots
f soft wood trees, mainly in the form of hydroxymatairesinol.
Lignans
some of the important phenolic compounds originating from
plant families like Vitaceae, Leguminaceae, Gnetaceae, and Dipterocarpaceae it has antioxidant properties, antifungals, and pharmacological and therapeutic uses.
Stilbenes
What is the best-known stilbene?
Reveratrol
plant-derived antinutrients because they can precipitate proteins, inhibit digestive enzymes, and reduce vitamin and mineral utilization.
Tannins
Different colors, textures, and durability of leathers were achieved by using different formulations of plant tannins referred to as
Tanning liqueurs
T/F. Unripened fruits are high in tannin content. The high tannin content discourages fruit-eating animals from consuming the fruit until the seeds are mature and ready for dispersal.
TRUE
It is responsible for many of the enchanting colors seen in flowers
and the final beauty of autumn leaves.
Tannins
a protective agent against fungi, insects, or even herbivores, as a source of nitrogen necessary for the development of the plant, as growth regulating agents
similar to hormones, or as protective agents against ultraviolet radiation.
Alkaloids
used as major analgesics (morphine), antimalarial (quinine), to combat excess uric acid (colchicine), as a paralyzing substance (curare, caffeine), as poisons (strychnine, nicotine) as narcotics (cocaine, mescaline), as a cholinergic (pilocarpine), or as an anticancer (vinblastine, vincristine).
Alkaloids
They act directly on the nervous system with effects on consciousness and motor skills. The action on the nervous system can go as far as an antispasmodic, mydriatic, local anesthetic or analgesic, and narcotic action.
Alkaloids
can be roughly determined by cutting a knife or by applying pressure with a fingernail
Hardness
It involves burning splinter (match size stick)of wood in still air
Splinter ash test
The specimen burns to an as, which remains in the specimen and more or less retains the shape of the original
wood (splinter).
Full ash test
The residue drifts during the process of burning or the splinter leaves fine amounts of ash.
Partial ash test
Primitive cell type that gave rise, through evolution, to both vessel members and fibers.
Tracheid
It consists of a single elongated cell with pointed ends and a secondary, cellulosic wall thickened with lignin containing numerous pits but having no perforations in the primary cell wall.
Tracheids
It provides mechanical support and conducts upward motion of water.
Tracheids
Two types of tracheids
Longitudinal tracheids
Strand tracheids
Elongated cells with thickened cell walls and tapering pointed ends and its radial diameter decreases from earlywood to latewood
Longitudinal tracheids
90-94 % of softwood volume
Longitudinal tracheid
They are short cells that are arranged in longitudinal strings and have one or two square ends. It has bordered pits and is found near the resin canal
Strand tracheid
It is composed of living cells that are thin-walled, unspecialized in structure, and therefore adaptable to various functions
Parenchyma
It is alive and actively involved in photosynthesis, secretion, food storage, and other activities of plant life.
Parenchyma
Dead support tissues with thick walls
Sclerenchyma
Living support tissue with irregular walls
Collenchyma
It makes up the chloroplast-laden mesophyll of leaves and the cortex and pith of stems and roots. And also forms the soft tissues of fruits.
Parenchyma
Two types of parenchyma
Longitudinal parenchyma
Transverse cells
It has simple pits with relatively thin walled cells that forms strands with tapered ends. It contains darkly staining substances and when present it is not abundant.
Longitudinal parenchyma
This cells form the periphery of a structure called a resin canal. They may be thin or thick walled and also called epithelium.
Epithelial cells
What do transverse cells consist of?
Radial parenchyma
Ray tracheids
Epithelial cells
It is radially present and constitutes the rays, sometimes together with radial tracheids. It is involved in primary and secondary metabolism and transport.
Radial parenchyma
Its interior walls are either smooth or dentate and have relatively thick-walled cells. It is not universally present in all genera.
Ray tracheids
It is a part of a composite structure known as fusiform rays.
Epithelial cells
Also referred as resin ducts, they are technically not individual cells, but are actually open, tube-like spaces bordered by special cells that have the ability to secrete or pitch resin.
Resin canals
What is the purpose of resin canals?
To protect and seal up a wound by exuding resin to cover the damaged area of the tree.
It is a type of resin canal that is horizontal and can be used to identify if there is a presence of resin.
Fusiform ray
What are the two main types of Sclerenchyma?
Fibers and sclereids
It is greatly elongated cells whose long. tapering ends interlock, thus providing maximum support to a plant. It occurs in bundles or strands.
Fiber
It is an important sources of raw materials for textiles and other woven goods.
Fiber
It is extremely variable in shape and present in various tissues of plant, such as periderm, cortex, pith, xylem and phloem. Sometimes it is known as stone cells.
Sclereids
It is the support tissue of living elongated cells with irregular cell walls it has thick deposits of cellulose in their cell wall and appear polygonal in cross section.
Collenchyma
What is the dominant feature of separating softwoods from hardwoods?
The presence of pores or vessels in hardwoods
What is the function of longitudinal tracheids?
Mechanical support
What is the function of strand tracheids?
Water transport
What is the function of longitudinal parenchyma? and its orientation
Food storage and parallel to the long axis of the stem
What is the function of radial parenchyma? and its orientation
Food storage and water transport in radial direction and its perpendicular to the long axis of the stem
What is the orientation of the resin canal?
Parallel or perpendicular to the long axis of the stem
It is a group of non-structural components in woods and consists of both hydrophilic and lipophilic compounds.
Crystalliferous wood elements
It consists of terpenes and terpenoids located in resin canals and protects the tree from microbic attack. It secretes out where traumas to the tree have damaged the bark.
Oleoresin
It is a volatile component in softwood oleoresin, built up to two Isoprene units.
Monoterpenoids
One of the most important groups of extractives in softwood
Diterpenoids
mixtures of several related carboxylic acids, primarily abietic acid, found in tree resins
Resin acids
It is a special white pigment of the outer bark of the European birch (steroid)
Betulinol
It is located in the parenchyma cells of the tree and composed mainly of fats and waxes and is important in the metabolism of the tree.
Parenchyma resin
-when pores are bordered by other adjacent pores on both the vertical (radial) and horizontal (tangential) sides
Pore clusters
appear as bubble-like structures that
grow into open pores, and in some cases, completely stop-up the
pores of the heartwood.
Tyloses
What are the most notable monocots?
Palm and bamboo
the endgrain reveals a fairly simple structure of darker-colored fibrovascular bundles embedded
throughout a mass of lighter-colored parenchyma cells. Growth rings, sapwood/heartwood, and rays are all
completely absent.
Monocot
hollow in the center, with closed “nodes” generally occurring every few feet or so.
culm
abnormality or irregularity in the wood that arise from many different causes.
Wood defect
What are the most common defects found in tropical woods?
Knots
Reaction wood
Bark pockets
Pitch defects
Brashness
Man-made wood defects
incorrect milling, sawing and machining
Wood defects is the number one culprit in lowering woods ______, _____, and _______.
Strenght, durability and usefulness
the process of converting raw timber to forms suitable for woodworking or
construction projects.
Conversion
Shallow depressions on indentations in the surface of a board caused
by shavings or chips getting embedded in the surface during the process of dressing. They may be formed by a planer or jointer.
Chip mark
Wood in which the annual growth rings are at an angle with the axis of a piece as a result of sawing at an angle. In other words, rather than running parallel to the long edge of a board, for example, the grain runs at an angle to it. Such wood is not permitted for structural applications in the American Forestry Association guidelines because it lacks the same structural strength as an equal-sized piece that has the grain running parallel to the edge.
Diagonal grain
An irregularity in the surface of a board where wood fibers below the level of the dressed surface have been torn or broken out by a planer.
Torn grain
The presence of bark or the absence of wood on the corners or along the
length of a piece of lumber.
Wane
A darkening of the wood due to overheating by machine knives or rolls when pieces are stopped in the machine.
Machine burn
A depressed cut of the machine knives at the end of the piece.
Machine bite
A groove cut by the machine below the desired line.
Machine gouge
the process of drying lumber (either in a kiln or air drying) to an appropriate
level of moisture for woodworking and other commercial uses.
Seasoning
a nonspecific term that refers to a distorted or misshapen board.
warped
A curvature formed in the direction of the length of timber. A bowed board is flat, but bent, like a road going over a hill.
Bowing
a crack which separates the fibers of wood. It does not extend from one end to the other. It occurs across the growth rings and is usually caused by poor or improper drying processes.
Check
Where the board remains flat, but the ends move away from the center.
Another type of warp.
Crook
Where the board curves in length and width like a propeller.
Twisting
Where the face of a board warps up across its width such that if one looks at the end of the board, it will look like a shallow letter “U.” Is common with plain-sawn lumber.
Cupping
Occurs when the board remains flat in width, but curves in length like a
river going around a bend.
Spring
When lumber or timber is dried too quickly, wood shrinks much at the surface, compressing its damp interior. This results in unrelieved stress.
Case hardening
If case hardening is extreme it leads to
Honeycombing
the worst of drying defects because it’s irreversible and usually cannot be detected by looking at the face of the lumber.
Honeycombing
a separation of the wood through the piece to the opposite surface or to an adjoining surface due to the tearing apart of the wood cells.
Splits
Formed when a small piece of the bark protrudes into the lumber. This area is generally considered unsound.
Bark pockets
small injuries to the tree cause by birds, resulting in grain changes that later show up as various forms of figure or imperfections in the wood
birds pecks
a deformed growth formed when a tree receives a shock or injury in its
young age. Due to its injury, the tree’s growth is completely upset and irregular projections appear on the body of the timber.
Burls
If the tree grows rapidly, the annual rings are widened. It is known _______ timber and possesses less strength and durability.
Coarse grain
Anything that gives the wood a corrugated feel. Typically, this is caused by the harder summerwood rising above the softer springwood in the growth ring. The growth
rings do not separate.
Raised grain
A lengthwise crack or separation of the wood between the growth rings, often
extending along the board’s face and sometimes below its surface.
Heart shake
A crack in the heartwood, near the
centre of the tree. It is caused by poor
seasoning, or by using trees felled past maturity.
heart shake
Also known as “cup shake” or “wind shake,” this rupture runs parallel
to the growth rings.
Ring shake
The base of the branches forms a mark on the stem as new branches grow,
resulting in dark-coloured stains on the surface. These dark-coloured rings are due to the continuity of wood fibres and they are known as ______.
Knots
A knot that are not intergrown with the surrounding wood
Encased knot
These knots generally have splits and severe grain deviations near them.
Spike knots
a discoloration that penetrate the wood fiber. They’re caused by a
variety of conditions and can be any color other than the natural color of the wood. A number of non-wood destroying fungi can cause this.
Stains
Any form of wood discoloration caused by fungi. It’s typically found in dead
trees, so if the wood isn’t stabilized at the right time it will eventually become rotten wood.
Spalting
These are known as wandering hearts and caused by twisting of young trees by fast blowing wind. The timbers with twisted fibers is unsuitable for sawing.
Twisted fibers
What are the common effects of fungal damage?
Blue stain
Brown rot
Dry rot
Heart rot
Wet rot
White rot
Common in pine, maple, and many other woods, blue stain (also called
“sapstain”) is caused by a fungus that feeds on the sap. It does not live in live
trees due to lack of oxygen.
Blue stain
A form of wood decay
found only in softwoods
that destroys the wood’s
cellulose, eventually
causing cracks across the
grain.
Brown rot
After the wood that was
once infected with brown
rot dries out, the cell walls
of the remaining wood
begins to break down and
can be crushed to a dry
powder.
Dry rot
This is formed when a
branch has come out of
the tree. The heart wood is
exposed to an attack from
insects and the elements.
Ultimately, the tree
becomes weak and it
gives a hollow sound
when struck with a
hammer.
Heart rot
Kinds of fungi cause
chemical decomposition
of a wood’s timber. In
doing so it converts
timber into a greyish
brown powder known as
______ __.
Wet rot
This is just the opposite of
brown rot. It is a type of
fungi attack where the
wood’s lining and the
wood itself acquires the
appearance of a white
mass consisting of
cellulose compounds.
white rot
They damage fresh-cut
logs and unseasoned
lumber, but also attack
weakened, stressed,
dying trees, and
healthy trees with bark
injuries.
Pin-hole borers
Found in salty waters.
They form tunnels or
borers to take shelters.
Affected wood loses
its colour and strength.
No timber is
completely immune
from attack
Marine borers
It is indicated by abnormal brittleness, torn grain, low density, and relatively low color in the center of the heartwood. It commonly occurs near or at the center of the logs particularly in butt logs.
Brash center
These are round or irregular channels of varying lengths, and the diameter varies from 3/8 to 1 inch. This are caused by wood-consuming grubs that hatch from eggs.
Grub channels
This defect occurs in a log cut just at the base of a fork in which two separate pith centers appear and are often separated by a bark pocket.
Double pith
A log in which the pith is outside the geometrical center of the log. and are discarded for veneering
Off-center-pith
The tangential separation of fibers completely around a growth ring within the heart or core of the log. Resembling a ring shake but it is confined to the heart center only.
Loose heart
A single radial split that extends both sides of the pith.
Wind shake
A protuberance on the log which is overgrown with bark. It may be abrupt or only a gradual undulation which tapers back in all directions to the normal contour of the log.
Bump
A protuberance on the log which is sound, hard and round or horizontally ridged without protruding limbs, twigs or stubs.
Burl
Openings in the bark that expose the sapwood and sometimes the heartwood portion.
Wounds
What are the two kinds of wounds?
Old and new wound
It is called ____ if the sapwood of a log has been attacked by grub worms.
Wormy
This is characterized by tangential bands or rings of dark reddish-brown in the sapwood zone.
Pathological Heartwood
Presence of residual drying stresses brought about by tension in the wood core and/or compression in the shell
Case hardening
