Biology - 12.Plant anatomy and plant physiology

Three tissue systems,Dicot and monocot leaf,root and stem,Plastids,Chloroplast,Photosynthesis,Light and dark reaction,Mitochondria,Types of respiration,Respiratory quotient

Define respiratory quotient.

• The ratio of the volume of CO₂ liberated and the volume of O₂consumed during respiration.

• RQ = Volume of CO₂ liberated/volume of O₂ consumed

Explain the stages of Aerobic respiration.

C₆H₁₂O₆ + 6O₂ —> 6CO₂ + 6H₂O + ATP

STAGES OF AEROBIC RRESPIRATION:

1. GLYCOLYSIS

   • Breaking down - 1 molecule of glucose - 2 molecules of pyruvic acid.

   • Location - cytoplasm.

   • First step - aerobic & anaerobic respiration.

2. KREBS CYCLE

   • `Location - mitochondria matrix.

   • Oxidation - pyruvic acid - CO₂ and water.

   • “Tricarboxylic Acid Cycle”

3. ELECTRON TRANSPORT CHAIN

   • Location - inner membrane of mitochondria.

   • NADH+H⁺ and FADH₂ - oxidised - NAD⁺ and FAD - release energy via electrons - trapped by ADP to synthesize ATP.

   • Called “Oxidative Phosphorylation”

In this cycle,O₂,the ultimate acceptor of electrons gets reduced to CO₂ and water.

Types of cellular respiration

1. Aerobic respiration - with oxygen

2. Anaerobic respiration - without oxygen

Functions of mitochondria

• Main organelle - cell respiration

• Produce many ATP molecules - “Powerhouse of the cell” or “ATP factory of the cell”

• Maintains normal concentration - calcium ions

• Regulates - metabolic activity

Explain the structure of mitochondria

1. MITOCHONDRIAL MEMBRANE

   • Inner and outer membrane

   • Outer membrane — smooth,permeable

   • Inner membrane — semi-permeable,regulates material

2. CRISTAE

   • Inner membrane - minute finger like projections

3. OXYSOMES

   • minute regularly spaced tennis racket shaped particles

   • ATP synthesis

4. MITOCHONDRIA MATRIX

   • complex mixture - lipids and proteins

   • Mitochondrial ribosomes(70s),enzymes for kerbs cycle,tRNAs,Mitochondrial DNA

Factors affecting photosynthesis

1. INTERNAL FACTORS

   • Leaf age

   • Hormones

   • Accumulation of carbohydrates

   • Pigments

2. EXTERNAL FACTORS

   • Temperature

   • Water

   • Light

   • Carbon dioxide

   • Mineral elements

Two types of photosynthetic pigments?

1. Primary pigments — Chlorophyll a

2. Accessory pigments — chlorophyll b & carotenoids

Functions of chloroplast?

1. Storage of starch

2. Storage of lipids

3. Synthesis of fatty acids

4. Photosynthesis

5. Formation of chloroplasts

Father of plant anatomy

Nehemiah Grew

Define plant anatomy

Study of internal structure of plants

What are tissues?

Tissues are a group of cells that are similar or dissimilar in stucture or origin but perform similar function.

Based on ability to divide,types of tissues?

• Meristematic tissues

• Permanent tissues

Who classified the tissue system and what is the types of tissue systems?

• Sachs

  • Epidermal or dermal tissue system

  • Ground tissue system

  • Vascular tissue system

End products of light and dark reaction?

• Light reaction — ATP and NADPH₂

• Dark reaction — Glucose

Expand:

• ATP

• ADP

• NAD

• NADP

• Adenosine Tri Phosphate

• Adenosine Di Phosphate

• Nicotinamide Adenine Dinucleotide

• Nicotinamide Adenine Dinucleotide Phosphate

Define

• External respiration

• Cellular respiration

• Exchange of gases between organism and environment

• In cell,when food is oxidised to obtain energy

Discovery of mitochondria

Kolliker

Mitochondria is also known as ___________

Power house of the cell

What is photosynthesis and mention its reaction

Autotrophic organisms(algae,green plants & chlorophyll containing bacteria) - sunight - own food

6CO₂ + 12H₂O ———> C₆H₁₂O₆ + 6H₂O + 6O₂ ↑

Carbon dioxide + water (light & chlorophyll) ———> glucose + water + oxygen

Occurs in all green parts of plant,especially in green leaves.

What are photosynthetic pigments?

• Primary pigment - chlorophyll a - traps solar energy - converts it into chemical and electrical energy - reaction centre

• Accessory pigment - chlorophyll b & carotenoids - send absorbed energy to primary pigment - harvesting centre

Functions of mitochondria and chloroplast

CHLOROPLAST:

• Photosynthesis

• Storage of starch

• Storage of lipids

• Synthesis of fatty acids

• Formation of chloroplasts

MITOCHONDRIA:

• Maintain normal concentration of calcium ions

• Regulates metabolic activity of cell

• Powerhouse of the cell or ATP factory of the cell

  • Main organelle of cel respiration

  • Produce large number of ATP molecules

Differentiation of ground tissue system

1. Cortex

2. Endodermis

3. Pith'

4. Pericycle

What are passage cells?

Endodermis cells without casparian strips

Define protoxylem lacuna

In mature vascular bundle,Lower most protoylem disintegrates and forms a cavity. It is known as protoxylem lacuna.

Function of

• Xylem

• Phloem

• Conduction of water

• Translocation of food

Functions of epidermal system?

1. Epidermis — protects inner tissues

2. Stomata — transpiration

3. Root hairs — absorption of water & minerals

Vascular tissue system

I. RADIAL

• Xylem & phloem - different radii - alternating

• ex: roots

II. CONJOINT

• Xylem & phoem - same radius

1. COLLATERAL » Xylem - centre and phloem - periphery.Types,based on presence of cambium - open and closed.ex: dicot stem.

2. BICOLLATERAL » Phloem - inner & outer sides - Xylem.ex: cucurbita

III. CONCENTRIC

• Xylem completely surrounds phloem or vice versa.

• Types - Amphivasal,ex:dracaena & amphicribal,ex:ferns

Example for endarch

Stem

What is

• Endodermis

• Casparian strips

• bulliform cells

• Bundle sheath

• Innermost layer of cortex

• Band like thickening made of suberin

• Cells of upper epidermis that are large and thin-walled

• Parenchymatous cells that surround vascular bundle

Also known as

• Endodermis

• Epiblema

• Mitochondria

• Krebs cycle

• Primary pigments

• Accessory pigments

• Light dependent reaction

• Light independent reaction

• Starch sheath

• Rhizodermis/piliferous layer

• Powerhouse of the cell/ATP factory of the cell

• Tricarboxylic Acid Cycle

• Reaction centre

• Harvesting centre

• Light reaction/Hill’s reaction

• Biosynthetic pathway/Dark reaction/Calvin cycle

Structure of chloroplast

• Green plastids containing green pigments called chlorophyll

• Oval shaped organelles

• diameter - 2 to 1 micrometer

• thickness - 1 to 2 micrometer

1. ENVELOPE:

   Outer and inner membrane separated by intermembrane space

2. STROMA

   Matrix present inside membrane

   Contains DNA,70s ribosomes,other moelcules fo protein synthesis

3. THYLAKOIDS

   Thylakoid membrane encloses thylakoid lumen

   Photosynthetic pigments present

4. GRANA

   Thylakoids form a stack of disc like structures called grana

   Interconnected by stroma lamella

Artificial photosynthesis

Producing renewable energy by using sunlight

Cambium

Secondary growth

Which is formed during anaerobic respiration?

Ethyl alcohol