Medicinal Plants Lecture 9 2023/2024 PDF

Medicinal plants 2023/2024 Lecture 9 Dr. Amal F. Soliman Associate Professors of Pharmacognosy  ‫أجزاء المنهج‬ ❑ Anatomy (Lectures 1, 2, 3, 4, 5,6) ❑ Dusting powders (Lecture 7) ❑ Taxonomy (Lecture 8) ❑ Physiology Today's lecture (Lectur...

Medicinal plants 2023/2024 Lecture 9 Dr. Amal F. Soliman Associate Professors of Pharmacognosy  ‫أجزاء المنهج‬ ❑ Anatomy (Lectures 1, 2, 3, 4, 5,6) ❑ Dusting powders (Lecture 7) ❑ Taxonomy (Lecture 8) ❑ Physiology Today's lecture (Lecture 9) ❑ Introduction to Pharmacognosy  Photosynthesis ▪ Photosynthesis is a process in which simple organic substance like glucose is synthesized from simple molecules (H2O and CO2) by the green substance-containing plants. ▪ This process needs energy which is supplied by the sun light. ▪ The overall process is summarized as follows: 6H2O + 6CO2 → C6H12O6+ 6O2 ▪ Problem 1: How can plants make high energy glucose from low energy CO2? The energy to do this comes from light. ▪ Problem 2: Plants cannot use light energy directly. They convert the light energy to chemical energy (energy stored in molecules). Photosynthesis has three basic steps: 1. Energy is captured from the sunlight. 2. Light energy is converted into chemical energy in the form of ATP and NADPH. 3. Chemical energy is used to power the synthesis of organic molecules (e.g. carbohydrates) from carbon dioxide (CO2). ▪ First let's look at the structure of chloroplast. Chloroplast contains stacks of flattened organelles called a thylakoid. One stack of thylakoids is called a granum. Granum float within a cytoplasm-like fluid in the chloroplast called stroma. ▪ Chlorophyll a & b are present in higher plants. ▪ Chlorophyll a is the only pigment directly involved in the light reactions. ▪ Chlorophyll b only transmits absorbed energy to Chlorophyll a The photosynthesis process consists of two series of reactions: ▪ The light dependent reactions (in thylakoid membrane). ▪ The light-independent reactions (the Calvin cycle) in the stroma. Light-dependent reactions Electron carrier  The process of converting energy from a Photophosphorylation light-excited electron into the pyrophosphate bond of an ADP molecule  Light-independent (Dark) reactions (Calvin cycle) Ribulose 1,5 bisphosphate 3-phospho-glyceric acid From light reaction 3CO2 ½ C6H12O6 6CO2 C6H12O6 Glyceraldehyde-3-phosphate ‫لالطالع فقط‬ An Overview of Photosynthesis  Respiration ▪ Is the break down of complex molecules (sugars) to simple ones and release their energy in the form of ATP and the electron carriers (NADPH and FADH2) to build and maintain themselves. ▪ Plants use photosynthesis to store light energy into sugars and use respiration to break down these sugars and transfer their energy to ATP.  1. Glycolysis (Anaerobic Respiration). Phases of cellular 2. Formation of Acetyl Coenzyme A. respiration 3. Krebs cycle (tricarboxylic or citric acid cycle). 4. Oxidative phosphorylation: electron transport and chemiosmosis. Start with glucose and end with ATP(energy)  1 ▪ It occurs in the absence of oxygen (anaerobic). ▪ Glycolysis splits glucose (C6) into two molecules of pyruvic acid (C3). ▪ Four ATP and two NADH molecules are produced (net result 2 ATP) as 2 ATP were consumed. 2 FORMATION OF ACETYL COENZYME A Net results 6 NADH + 2 GTP+ 1 3 CITRIC ACID CYCLE FADH2 from 2 pyruvate molecules FADH2 4 OXIDATIVE PHOSPHORYLATION: ELECTRON TRANSPORT AND CHEMIOSMOSIS 34 ATP Respiration is a source of metabolites  ▪ Fill in A, B and C ? ▪ In plants, the process of photosynthesis takes place in the mesophyll of the leaves, inside the ……………………… Give only the term corresponding to the following sentences: - The process by which plants, some bacteria, and some protistans use the energy from the sunlight to produce sugar. The enzymatic path for splitting sugar into pyruvate in plants. ▪ Mention the three important stages of Calvin cycle? ▪ What is A ? ▪ Choose Calvin cycle refers to the ……………. reactions in photosynthesis. (Light-dependent or light-independent) ▪ Fill in A, B and C ? Choose ▪ A given plant name as following, Syzygium aromaticum L. The letter (L.) refers to: a. Author name b. Abbreviation of family c. Order of the plant d. None of the previous ▪ Monocot leaves are characterized by their: a. Parallel venation b. reticulate venation c. needle-shaped leaves d. quadrable stems ▪ To which of the followings, does Garlic belong ? a. Fabaceae b. Solanaceae c. Liliaceae d. Brassicaceae ▪ Diacytic stomata and Labiaceous trichomes are characteristic features of family? a. Lamiaceae b. Solanaceae c. Asteraceae d. Brassicaceae