Plant and Animal Nutrition

Nutrition

• The process of obtaining food for health and growth.
• The science that interprets nutrients and other substances in food for maintenance, growth, reproduction, health, and disease.
• Includes food intake, absorption, assimilation, biosynthesis, catabolism, and excretion.

Modes of Nutrition in Plants and Animals

• Autotrophs are self-feeders.
• They produce food from inorganic materials at the primary level of a food chain.
  • This includes photoautotrophs and chemoautotrophs.
  • Examples are plants, algae, some bacteria, and archaea.
• Heterotrophs aren't producers.
• They are consumers that get food by eating other organisms at the secondary and tertiary levels of a food chain.
  • This includes herbivores, carnivores, omnivores, and detritivores (scavengers).
  • Examples are animals, fungi, some bacteria, protists, and parasitic plants.
• Macronutrients are required in amounts above 0.5% of the plant's dry weight.
  • They are energy-providing nutrients.
  • Examples are Nitrogen (N), Phosphorus (P), Potassium (K), Sulfur (S), Calcium (Ca), Magnesium (Mg), Carbon (C), Hydrogen (H), Oxygen (O).

Micronutrients

• Required in minute or trace amounts.
• They help in the prevention of diseases.
  • Includes Iron (Fe), Manganese (Mn), Copper (Cu), Zinc (Zn), Boron (B), Chloride (Cl), and Molybdenum (Mo).

Nutrition Requirements of Plants

• Sunlight is needed.
• Water is needed.
• Carbon Dioxide is needed.

Apoplastic Pathway

• Water is transported from root hair to xylem through the cell wall of intervening cells or intercellular pathway.
• Least affected by the metabolic state of the root.

Symplastic Pathway

• Utilized to deliver water and ions over the cortex through plasmodesmata.
• Offers resistance to the flow of water and is affected by metabolic states of the root.

Calorie

• A unit of energy from food and drink, related to physical activity and heat.
• Nicolas Clement first introduced calories as a unit of heat energy.
• Carbohydrate (4 calories), Fat (9 Calories), Protein (4 Calories).

Caloric Balance

• Isocaloric Balance: weight maintained; energy in = energy out.
• Negative Caloric Balance: weight loss; energy in < energy out.
• Positive Caloric Balance: energy in > energy out.

Carbohydrates

• Most common biomolecule and the primary source of energy for the body.
  • (CH2O)n
  • Glucose Units

Proteins

• Building blocks of generic material in all living systems comprised of combinations of the same 20 distinct amino acids.
  • Consist of Amino Acids

Fats or Lipids

• Energy-giving molecules or stored-energy molecules that store more energy than carbohydrates and proteins.
  • CH3(CH2)COOH
  • Triglyceride

Essential Nutrients

• Amino Acids: Eight of the 20 amino acids cannot be synthesized by humans.
  • This includes Lysine, Tryptophan, Threonine, Methionine, Phenylalanine, Leucine, Isoleucine, and Valine.
• Fatty Acids: used for making special membrane lipids.
  • This includes Linoleic Acid (2 double bond) and Linolenic Acid (3 double bonds).
  • They are found in sunflower, corn, and sunflower oils (polyunsaturated veg.oil).

Vitamins

• Organic molecules required in small amounts for normal metabolism.
  • Fat-Soluble: Vitamins A, D, E, K
  • Water-Soluble: Vitamins B, B2, B3, B12, C

Trace Elements or Minerals

• Inorganic nutrients needed by the body in minute amounts.
• They form part of enzymes, body tissues, and body fluids.
  • This includes lodine, Cobalt, Zinc, Molybdenum, Manganese, and Selenium.

Vitamins Functions

• Vitamin A for vision, skin rejuvenation, bone and tooth growth, reproduction, and immunity.
• Vitamin D (D2, D3 or Calciol, Calcidol, Calcitriol) for mineralization of bones.
• Vitamin E (Alpha-tocopherol) as antioxidant and for stabilization of cell membranes.
• Vitamin K (Phylloquinone, Menaquinone, Memadione, Napthoquinone) for synthesis of blood-clotting proteins and bone proteins.
• Vitamin B1 (Thiamine) changes carbohydrates into energy.
• Vitamin B2 (Riboflavin) helps metabolize carbohydrates.
• Vitamin B3 (Niacin) lowers cholesterol, eases arthritis, and boosts brain function.
• Vitamin B5 (Pantothenic Acid) breaks down fats and carbohydrates for energy.
• Vitamin B6 (Pyridoxine) is needed for normal brain development and for keeping the nervous system and immune system healthy.
• Vitamin B7 (Biotin) helps the body metabolize fats, carbohydrates, and protein.
• Vitamin B9 (Folate) is for red blood cell formation and for healthy cell growth and function.
• Vitamin B12 (Cobalamin) forms blood cells and DNA.
• Vitamin C (Ascorbic Acid) forms blood vessels, cartilage, muscle, and collagen in bones; also vital for the body's healing process.

Three Types of Endocytosis

• Phagocytosis: engulfment of organic fragments or big particles (Cell Eating)
  • Pseudopod formation in Amoeba
• Pinocytosis: uptake of extracellular fluid by a cell using small vesicles derived from the plasma membrane (Cell drinking)
• Receptor-Mediated Endocytosis: relies on membrane receptor recognition of specific solutes which are then taken up by the cell via receptor-coated pits

Feeding Mechanisms in Animals

• Filter Feeding obtains nutrients from particles suspended in water.
  • Performed by Sea Creatures
• Deposit Feeding obtains nutrients from particles suspended in soil.
  • Carried out by Scavengers
• Fluid Feeding: obtaining nutrients by consuming other organisms' fluids.
  • Examples include Mosquitoes
• Bulk Feeding: obtaining nutrients by eating all of an organism.
  • Humans are an example

Different Kinds of Digestive Compartment

• Food Vacuoles in Unicellular Organisms
  • These fuse with lysosomes that contain hydrolytic enzymes.
  • Food vacuole in a protozoa like Paramecium
• Gastrovascular Cavity or Incomplete Digestive System: A single opening used for taking in food and disposing of waste; a saclike body cavity.
• Worms.
• Complete Digestive System: Like a tube with an opening at one end (mouth) and an opening at the other end (anus).
  • Specialized organs between the mouth and anus transport, process, and absorb digested nutrients.
  • Humans are the only ones that have this.

Main Stages of Food Processing

• The time duration for food to travel from entering the mouth to being excreted: 30 to 40 hours.
  • Includes Ingestion, Digestion, Absorption, and Elimination.

Human Digestive System

• Mouth: food is initially shredded by teeth and mixed with saliva.
  • Salivary Glands; secrete saliva that moistens and helps break down food which comes in three pairs.

Pharynx

• The entrance to the esophagus that connects the mouth to the esophagus
  • Epiglottis; a flap-like valve that closes the trachea to prevent food from entering the trachea.

Esophagus

• A muscular tube that connects the pharynx with the stomach and is about 10 inches long.
  • Peristalsis; the rhythmic waves of contraction of the smooth muscle that pushes food into the stomach

Stomach

• Ingested food is mixed, stored, and broken down into a liquidy mixture.
• Secretes gastric juice and regulates the passage of food into the small intestine.
  • Gastric Juice; a combination of HCI and acid-stable proteases that helps dissolve and degrade food, particularly proteins.

Small Intestine

• Approximately 6 meters long and is consist of three regions, that absorb nutrients from already-digested food.
  • Duodenum; where complete digestion of carbs, fats, and proteins occurs (about 25 cm).

Large Intestine

• Shorter than the small intestine, does not coil up, and does not have villi.
• The last structure to process food, stores undigested matter by absorbing mineral ions and water.
  • Colon; Ascending Colon, Transverse Colon, Descending Colon, and Sigmoid Colon (Four Parts).
• Rectum and Anal Sphincter.

Accessory Digestive Organs

• Pancreas produces juice to break food into sugars, fats, and starches.
• Liver secretes bile for digestion, elimination, and fat absorption.
• Gallbladder stores bile produced by the liver until needed.

Gas Exchange (Respiratory Exchange)

• The uptake of molecular oxygen from the environment and the discharge of carbon dioxide into the environment
• Oxygen; is needed in tissues for aerobic respiration to occur and extract ATP from food
• Carbon Dioxide; must be released to prevent physiological pH in tissues from being acidic.

Basic Principles Influencing Gas Exchange

• To allow gas exchange, the environment should be moist, large enough, and protected from desiccation.
• Respiratory Systems rely on the diffusion of gases down pressure gradients.
  • Ficks's Law; the amount of diffusion of a gas across a membrane is proportional to the surface area and the difference in partial pressure between the two sides and inversely proportional to the thickness of the membrane (gas exchange is fast when the area for diffusion is large and the path for diffusion is short - respiratory surfaces tend to be large and thin)
• Surface area-to-volume Ratio: gases and food molecules dissolved in water must be absorbed and waste products must be eliminated.
  • surface area to volume ratio gets smaller as the cell gets larger; As a cell grows bigger, its internal volume enlarges, and the cell membrane expands.
• Ventilation: the movement of the respiratory medium (air or water) over the respiratory surface.
  • Bony fishes move the gill covers (operculum) for water carrying oxygen to flow across the gill.
  • Humans move the muscles of the thorax to expand and contract the chest activity and move air in and out of the lungs.
• Respiratory Pigments or Protein adaptations of animals for gas exchange include those that bind and transport gases.
  • Blood cannot carry sufficient oxygen and carbon dioxide in dissolved form to meet the body's requirements.

Structures for Gas Exchange in Plants

• Stomata in Leaves
  • Minute openings in the epidermis of leaves, stems, and other plant parts.
  • Permits the movement of gases (oxygen, carbon dioxide, and water vapor) to diffuse between the plant tissues.
• Lenticels in Stem
  • Porous tissue with large intercellular spaces in the periderm of woody stems and roots of dicotyledonous flowering plants.
  • Provide a pathway for gas exchange between internal tissues and the atmosphere.
• Root Hairs in Aerial Roots
  • Roots that are extensions of the root's external cells.
• Pneumatophores or Lateral Roots of Mangroves
  • Specialized root structures that grow out of the water surface.
  • Facilitate aeration for root respiration in hydrophytic trees (e.g. mangrove species).
  • Examples are Avicennia Germinans, Lagunulari Raecemosa, Bald Cypresses, Cotton (Tupelo) hum (Nyssa Aquatic), and Red Mangroves (Rhizophora Mangle).

Respiratory Surfaces in Invertebrates

• Cell Surface or Cell Membrane
  • Used in unicellular organisms (bacteria, etc.).
  • Diffusion is rapid because the distance is so small.
• Integumentary Exchange
  • The general body surface or skin used by animals with a high surface-to-volume ratio (earthworms, leeches, etc.).
• External Gills
  • Gill that projects from the surface
• Tracheal System
  • Utilizes fine air-conducting tubules to provide gaseous exchange at the cellular level
  • Independent (mosquitoes, insects, spiders, etc.).

Respiratory Surfaces in Vertebrates

• External Gills
  • Thin, vascularized epidermis.
• Internal Gills
  • Rows of slits in adult fishes positioned at the back of the mouth allowing water flow-over.
• Lungs
  • Internal respiratory surfaces, shaped as a cavity or sac, provide a membrane for gaseous exchange since they are not in direct contact.

Birds Gas Exchange

• Use a system of air sacs as a blower to keep air flowing through the lungs in one direction only preventing the mixing of incoming and outgoing air.
• Countercurrent Flow: water flows over the gills and blood circulates.

Human Respiratory System

• A series of organs responsible for taking in oxygen and expelling carbon dioxide.
  • Includes components like the Nasal Cavity, Pharynx, Larynx, Trachea, Bronchi, Lungs.
• Nasal Cavity
  • Two holes or nostrils located in the nose open behind the nasal cavity moisten
• Pharynx
• Passageway that leads into the voice box
• Larynx (Voice Box)
  • Lies at the top of the trachea also has a pair of vocal cords

4. Trachea (Windpipe)

• About 10-12 cm supported by 15-20 to prevent a collapsing trachea

5. Bronchi (Bronchus)

• Lower end of the trachea that enters left and right lungs

6. Lungs

• This organ resides inside the Thoracic Cavity

Xylem

• A complex tissue in plants responsible for transporting water that stems from root

Phloem

• A complex tissue in plants for transporting compounds made in photosythesis

Water and Needs for Plants

• Growth
• Photosynthesis
• Distribution of Inorganic Molecules
• Plants Transpiration in Plants
• Absorpion of Vapor of Water
• Root System

Transport

• This helps with gases across body
• Simple Diffusion
• Circulatory System

Human Circulatory System

• Contains independents: -Cardiovascular -Lungs -Artery