Lecture 5: Gums and Mucilage

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Questions and Answers

What is the primary characteristic of chlorenchyma tissue?

It is involved in mechanical support.

It contains chloroplasts for photosynthesis. (correct)

It stores water and nutrients.

It facilitates gas exchange in plants.

Which of the following shapes can chlorenchyma tissue have?

Only elongated, resembling fibers.

Either elongated or rounded. (correct)

Only rounded, resembling spheres.

Both elongated and cubical shapes only.

What type of tissue is chlorenchyma classified as?

Parenchyma (correct)

Sclerenchyma

Xylem

Collenchyma

In which part of the plant is chlorenchyma primarily located?

Leaves Signup and view all the answers

Which type of chlorenchyma is primarily responsible for maximal light absorption in leaves?

Elongated chlorenchyma Signup and view all the answers

What is one primary function of the cell wall in plant cells?

Protects the contents of the cell Signup and view all the answers

Which type of tissue is responsible for conduction in plants?

Vascular tissue Signup and view all the answers

Which type of cells in the dermal tissue are typically devoid of chlorophyll?

Epidermal cells Signup and view all the answers

What characteristic of epidermal cells distinguishes them from other types of plant cells?

Coverage with cuticle Signup and view all the answers

What is the first step in the microscopical examination process described?

Observing the shape Signup and view all the answers

Which of the following is NOT a function of parenchyma cells?

Conduction of nutrients Signup and view all the answers

In what medium should the microscopical mounts be prepared?

Dilute glycerin Signup and view all the answers

Which of the following is NOT a parameter to be examined microscopically?

Color Signup and view all the answers

What does the term 'hilum' refer to in the context of microscopical examination?

A point on the structure of the specimen Signup and view all the answers

What is the final step mentioned in the examination process?

Drawing a labeled sketch Signup and view all the answers

What type of waste product is calcium oxalate?

Inorganic waste product Signup and view all the answers

What reaction leads to the formation of calcium oxalate in plants?

Calcium from soil and oxalic acid Signup and view all the answers

Which of the following statements regarding calcium oxalate is true?

Insoluble in alcohol Signup and view all the answers

What does calcium oxalate contain that is characteristic of its structure?

Three molecules of water of crystallization Signup and view all the answers

What effect does prolonged exposure to a KOH solution have on calcium oxalate?

Affected after a long time Signup and view all the answers

What is a primary difference between organized and unorganized drugs?

Organized drugs have a specific structure while unorganized drugs do not. Signup and view all the answers

Which characteristic distinguishes official drugs from non-official drugs?

Official drugs have been approved by regulatory authorities. Signup and view all the answers

What is a key difference between primary and secondary metabolites?

Primary metabolites are crucial for plant growth, while secondary metabolites are responsible for reproduction. Signup and view all the answers

What distinguishes gums from mucilage in terms of their formation?

Gums are pathological products formed by plant injury, while mucilage is physiological. Signup and view all the answers

What differentiates upper epidermis from lower epidermis in plant leaves?

Lower epidermis contains chloroplasts, while upper does not. Signup and view all the answers

Which of the following statements about gums is correct?

Gums are translucent, amorphous solids that are insoluble in alcohol. Signup and view all the answers

Which statement correctly describes the role of guard cells compared to epidermal cells?

Guard cells can change shape to open and close stomata, while epidermal cells cannot. Signup and view all the answers

What are the primary components that form gums and mucilage?

Complex polysaccharides made from sugars and uronic acid units. Signup and view all the answers

What type of fibers do gums and mucilage represent?

Both dietary and functional fibers. Signup and view all the answers

Which of the following elements are commonly found in the composition of gums?

Calcium, potassium, and magnesium salts. Signup and view all the answers

Study Notes

Lecture Information

Lecture number 5
Week number 5
Dates: October 25-31, 2024

Gums and Mucilage

Gums, mucilage, and pectins are complex polysaccharides
Formed from sugars and uronic acid units
Are dietary and functional fibers

Gums

Pathological products formed by plant injury
Amorphous, translucent solid, insoluble in alcohol and most organic solvents
Composed of calcium, potassium, and magnesium salts of complex polyuronides

Mucilage

Physiological products
Forme during plant metabolism
Formed from or deposited in cell walls in successive layers
Normal plant metabolic products obtained without injuring the plant

Gums Formation

Gum tragacanth: formed in pith and medullary rays, known as gummosis
Air hardened gummy exudate from Astragalus gummifer family
Exudes rapidly after incision (2-year-old trees)

Gum Acacia

Exudes slowly (6-year-old trees)
Obtained from stem or branches of Acacia senegal
Exudes after (20-30 days)
Formed from cambium cells during new phloem formation

Gum Composition

Composed of two parts: tragacanthin (soluble in water) and bassorin (insoluble in water).
Best type has least amount of tragacanthin
Insoluble in alcohol
Contains peroxidase enzyme and starch

Additional Information

By prolonged boiling with dilute acid, a mixture of sugars and uronic acids is formed.
Different types of mucilage exist (neutral, acidic, seaweed/agar)

Plant Cell Structures and Functions

Cell: Structural and functional unit of all living things
Cytology: Study of cells
Plant cells: Have vacuoles for transporting and storing nutrients, water, and waste products; contain plastids (e.g., chloroplasts) for synthesizing and storing food; have a rigid cell wall
Turgor pressure: Outward force in a plant cell when vacuoles fill up with water and pushes cell membrane against cell wall

Plant Cell Tissues

Dermal tissue: Epidermis (single layer of cells around leaf; upper and lower epidermis are flat with no chloroplasts to allow light passage; cells are covered with cuticle)
Ground tissue: Parenchyma (cells are rounded or irregular with thin walls and narrow intercellular spaces); Chlorenchyma (elongated: palisades of a leaf, or rounded: spongy tissue; mostly contains chloroplasts); Collenchyma and Sclerenchyma (supporting tissues, Collenchyma has thickened walls and sclerenchyma has lignified walls)
Vascular tissue (Xylem and Phloem) are responsible for support and conduction in plants

Stomata

Stomata are pores in leaves, mostly on the undersurface
Each pore is surrounded by a pair of guard cells
Guard cells control the opening and closing of the stomata, regulating gas exchange (carbon dioxide and oxygen).

Stomata Types in Dicots

Anomocytic: Surrounding cells vary in number (4-8) and have no special arrangement
Diacytic: Surrounding cells (2) have longitudinal axis perpendicular to the pore
Paracytic: Surrounding cells (2) have longitudinal axis parallel to the pore
Anisocytic: Surrounding cells (3 or more), one of which is noticeably smaller

Guard Cell Differences

Guard cells have chloroplasts
Guard cells are bean-shaped
Guard cell walls are not evenly thick

Leaf Internal Structure

Layers include cuticle, upper and lower epidermis, palisade mesophyll, spongy mesophyll

Epidermal Hairs

Non-glandular hairs (covering trichomes)
Glandular hairs (with swollen heads)

Other General Information

Types of Stomata in Dicotyledons and Monocots (specific classifications)
Cell Walls (functions, chemical modifications.)

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Description

This quiz covers the properties and formation of gums and mucilage, which are complex polysaccharides derived from plant metabolism and injury. Learn about their composition, types, and functions in dietary and functional fibers. Test your understanding of these essential plant products in the context of botanical studies.