Ch. 15 &16: Plant Physiology

Major parts of a flower

Plant Cell

How plants produce food Photosynthesis – a series of processes in which light energy is converted to a simple sugar.

Chlorophyll – green material inside the leaves and stems of the plant that gives the plant its green color. Chloroplasts – small, membrane-bound bodies inside cells that contain the green chlorophyll pigments. These are the sites of the actual conversion of solar energy into stored energy.

Photosynthesis 6CO 2 + 6H 2 O >> C 6 H 12 O 6 + 6O 2

Respiration Exchange of oxygen and carbon dioxide C 6 H 12 O 6 + 6O 2 >> 6CO 2 + 6H 2 O +HEAT

Transpiration Process by which the plant gives up water vapor to the atmosphere. –Most plants transpire about 90% of the water they take in.

What causes plants to wilt? Lack of turgor pressure, caused from not having enough water. Turgor pressure – swollen or stiffened condition as a result of plant cells being full of water.

Purpose of soil Soil provides a natural environment for roots. It supplies air, water, and nutrients for the plant.

Plant nutrition There are sixteen essential elements for normal plant growth. –Macronutrients – elements used in relatively large amounts. –Micronutrients – elements used in small, or trace amounts.

Macronutrients C – carbon H – hydrogen O - oxygen Obtained from the atmosphere N – nitrogenCa - calcium P – phosphorusMg - magnesium K – potassiumS – sulfur

Micronutrients B – boron Cu – copper Cl – chlorine Fe – iron Mn – manganese Mo – molybdenum Zn - zinc

Soil pH pH – acidity level Acidic Alkaline (base) Neutral Optimum range for most plants