Photosynthesis & Nutrition

Life Processes

• Basic and essential functions that living organisms perform to maintain life.
• Nutrition is the process of obtaining and using food.
• Respiration is the process of breaking down food to obtain energy.
• Transportation transfers substances from one part of the body to others.
• Excretion removes waste materials produced in cells.

Nutrition

• Autotrophic nutrition: organisms make their own food from simple inorganic materials, such as green plants and autotrophic bacteria.
• Heterotrophic nutrition: organisms cannot synthesize their own food from inorganic materials and depend on other organisms.
• Holozoic: organisms consume and internally digest complex organic food, such as humans, dogs, cats, and amoebas.
• Saprophytic: organisms feed on dead and decaying organic matter, such as fungi, bread molds, yeast, and mushrooms.
• Parasitic: organisms derive nutrition from another living organism (host), often harming the host, such as lice, leeches, tapeworms, and dodder.

Photosynthesis

• Plants make their own food from carbon dioxide and water using sunlight energy in the presence of chlorophyll.
• Necessary conditions: sunlight, carbon dioxide, chlorophyll and water.
• $6CO_2 + 12H_2O \xrightarrow[\text{sunlight}]{\text{chlorophyll}} C_6H_{12}O_6 + 6H_2O + 6O_2$
• Light energy is absorbed by chlorophyll.
• Light energy is converted to chemical energy, splitting water molecules into hydrogen and oxygen.
• Carbon dioxide is reduced into carbohydrates.

Photosynthesis Site

• Chloroplasts are green organelles containing chlorophyll, found inside plant cells.
• Leaves are green because they contain chloroplasts.
• Guard cells regulate the opening and closing of stomata.
• Stomata are tiny pores present on the surface of leaves, through which CO2 enters.
• Water is taken up by roots from the soil.
• Nitrogen, phosphorus, magnesium, and iron are also absorbed. Nitrogen is taken up in the form of nitrates and nitrites.
• Food is stored as starch in plants and as glycogen in animals.

Experiment Demonstrations

• Boiling a leaf in water removes enzymes.
• Boiling a leaf in alcohol removes chlorophyll making the leaf colorless.
• Applying iodine solution to a leaf indicates the presence of starch.
• Green parts of a leaf indicate that chlorophyll is present.
• Green sections undergo photosynthesis.
• Non-green parts lack of chlorophyll and photosynthesis.
• KOH absorbs CO2, without it there is no starch observed.
• Starch is present at green sites showing chlorophyll's necessity for photosynthesis.
• Saliva breaks down starch.

Nutrition in Human Beings

• Teeth: crush and cut food into small pieces.
• Liver: Makes acidic food coming from the stomach alkaline and emulsifies larger fat globules.
• Pancreas: releases trypsin to digest proteins, and lipase to breakdown fats.
• Small intestine: site of complete digestion of fats, carbohydrates and proteins.
• Salivary glands: secrete saliva containing salivary amylase which breaks down complex carbohydrates to simple sugar.
• Esophagus: food pipe where peristaltic movement (contraction and expansion of wall) pushes food into the stomach.
• Gastric glands: hydrochloric acid creates acidic medium, pepsin digests enzyme digesting proteins, mucus protects stomach from acid.
• Herbivores have longer small intestines for cellulose digestion, whereas carnivores have shorter intestines for easier meat digestion.

Respiration

• The process of releasing energy from food.
• Physical breathing for inhaling and exhaling air with lungs.
• Chemical respiration breaks down food to produce energy (ATP) in cells.
• Alcoholic fermentation (anaerobic): Glucose → Ethanol + Carbon dioxide + Energy (in yeast).
• Lactic acid fermentation (anaerobic): Glucose → Lactic acid + Energy (in cytoplasm; in muscles during lack of oxygen).
• Buildup of lactic acid causes cramps during sudden muscle activity.
• Aerobic respiration: requires oxygen, produces more energy, involves complete glucose oxidation.

Aerobic vs Anaerobic

• Aerobic end products: $CO_2 + H_2O$. Occurs in the cytoplasm and mitochondria.
• Anaerobic: oxygen is not required, less energy is produced, incomplete glucose oxidation, occurs only in cytoplasm.
• Anaeroboic end products: $CO_2 + ethanol$ / lactic acid.

Nutrition in Amoeba

• Holozoic nutrition in a unicellular organism.
• Amoeba takes in food using temporary cell surface extensions called pseudopodia.
• Food vacuoles digest complex substances into simpler ones.
• Cytoplasm absorbs digested food by diffusion.
• Undigested food moves to the cell surface and is expelled.

Nutrition in Paramecium

• A unicellular organism with a definite slipper shape.
• Holozoic nutrition occurs.
• Food is moved to a specific spot by the movement of cilia.

Human Respiratory System

• Nostrils: air enters.
• Nasal passage: hairs and mucus filter air.
• Pharynx: common passage for food and air.
• Larynx: voice box containing vocal cords.
• Trachea: windpipe with cartilage rings preventing collapse.
• Bronchi: connect trachea to each lung.
• Bronchioles: branching tubes within lungs.
• Alveoli: sacks for the exchange of O2 and CO2.
• Diaphragm: Large muscle separating chest from abdomen.
• Residual volume is the amount of air always remaining in lungs.
• Haemoglobin is present in red blood cells to carry oxygen.
• Inspiration: diaphragm contracts, moves downward, chest cavity enlarges, air is sucked in.
• Expiration: diaphragm relaxes, moves upward, chest cavity shrinks, air is pushed out.

Respiration in Plants

• Gases exchange through stomata.
• Daytime: photosynthesis produces oxygen, respiration produces carbon dioxide, net O2 output.
• Nighttime: no photosynthesis, respiration produces carbon dioxide, net CO2 output.
• Fish: take in water through mouth, force it past gills, dissolved O2 is taken by blood.
• Terrestrial: Use oxygen in the atmosphere, lower breathing rate.
• Aquatic: Use dissolved oxygen in water, higher breathing rate.

Transportation in Humans

• The process of transferring substances from one part of the body to others.
• Uses circulatory and lymphatic systems.
• The circulatory system consists of the heart, blood, and blood vessels.
• The heart is a muscular organ about the size of a fist.
• Septum separates heart chambers and prevents mixing of oxygenated and deoxygenated blood.
• Ventricles have thicker walls than atria.
• Vena Cava: From upper/lower body to the right atrium.
• Aorta: Largest artery.
• Arteries: carry oxygenated blood away from the heart.
• Veins: return deoxygenated blood to the heart, contain valves.
• Pulmonary artery: carries deoxygenated blood.
• Pulmonary vein: carries oxygenated blood.

Blood Circulation

• Single circulation: blood passes through the heart once in a complete cycle.
• Double circulation: blood flows twice through the heart before a complete circuit.
• Valves in veins prevent backflow of blood.
• Blood components:
• RBCs: contain hemoglobin and transport oxygen.
• WBCs: fight infections and produce antibodies.
• Platelets: facilitate blood clotting.
• Plasma: fluid medium which transports food, carbon dioxide and nitrogenous waste.
• Features of Arteries: Transports blood away from the heart, oxygenated blood, thick & elastic walls, no valves, high pressure
• Features of Veins: Transports blood back to the heart, deoxygenated blood, thin & less elastic walls with valves, low pressure
• Capillaries are for material exchange, one-cell thick and without valves.
• Exceptions: Pulmonary artery carries deoxygenated blood, the Pulmonary vein carries oxygenated blood.

Lymphatic System

• Lymph is part of the lymphatic system formed from leaked blood components.
• It is a colorless fluid with less protein than blood.
• It carries digested and absorbed fat from the intestine.
• It drains excess fluid back into the blood.

Transportation in Plants

• Xylem and pholem conduct independent transport.
• Xylem: Transports water and minerals unidirectional from roots to aerial parts, uses physical forces like root pressure and transpiration pull.
• Pholem: Transports food bidirectional, uses active transport, with sieve tubes and companion cells.

Transpiration

• The loss of water by vaporation from aerial plant parts is called transpiration.
• Transpiration helps in absorption, upward water movement, mineral transport, and temperature regulation.
• Translocation transfers food from leaves to other plant parts.
• Phloem translocates food; substances delivered to storage organs and growing organs.
• Root pressure moves water into root xylem and pushes upwards.
• Daytime transpirational pull is the major force, nighttime root pressure takes over.

Excretion

• The human excretory system includes kidneys to remove nitrogenous waste from blood. Uses a pair of ureters connects kidneys with urinary bladder. A urinary bladder stores urine with muscular control. And uses a urethra transports urine out of the body.
• Nephron is the functional unit of kidney.
• Glomerulus: cluster of blood vessels.
• Bowman's capsule: cup-shaped structure surrounding glomerulus, collecting filtrate.
• Tubular section collects everything except useful material.
• Glomerular filtration: Nitrogenous wastes, glucose, water, amino acids, excessive salts are filtered from the blood into Bowman's capsule.
• Selective reabsorption: Useful substances like glucose, amino acids, salts, and water are reabsorbed by capillaries.

Artificial Kidney

• In kidney failure, artificial kidney (hemodialysis) removes nitrogenous waste.
• Uses a dialysing fluid in blood (without nitrogenous wastes).
• Uses dialysing solution is rich in urea and excess salts.

Plant Excretion

• Oxygen and carbon dioxide are diffused through stomata.
• Excess water is removed by transpiration.
• Plants shed old leaves and bark.
• Many plant waste products are stored in cellular vacuoles.
• Plants secrete some waste substances into the soil around them.

Control and Coordination

• Stimuli: Change in the environment to which an organism responds.
• Response: Reaction of an organism to a stimulus.
• Coordination: Working together of various body parts to respond to stimuli.
• Nervous system: The Peripheral nervous system (cranial nerves arise from the brain & spinal nerves come from the Spinal Cord) and the Central nervous system (CNS)
• Neuron: structural and functional unit of nervous system and largest cell in the body.
• Dendrites
• Cell body
• Axon
• Nerve ending

Transmission of Impulses

• Transmission of impulse between 2 Neurons
• Synapse is microscopic junction between two neurons where chemicals are released.
• Neurotransmitters: transmits of nerve impulse.
• Neuromuscular junction is between a nerve ending of motor neuron and a muscle.
• Sensory neurons transmit impulses from receptors to the CNS. Motor neurons transmit impulses from CNS to effectors and Relay neurons connects sensory and Motor neurons

Reflex Actions

• sudden and Quick movement.
• Involuntary movement, with brain not directly involved.
• Controlled by the spinal cord.
• Reflex arc is the path followed by nerve impulse during a reflex action.
• Brain coordinate the body, with connections to the spinal Cord.

Coordination in Plants

• Specialized tissues in animals conduct signals, change shape by proteins in muscles.
• No conducting tissues in plants, change shape by amount of water resulting in swelling/shrinking.
• Tropic Movements: Unidirectional, dependent on Growth with a slow action, occurs in all plants.
• Nastic Movements: Growth-independent & temporary in some plants

Animal Hormones

• Hormones are chemical messengers
• Gland produces specific substance.
• Endocrine gland: ductless, secrete into bloodstream.
• Exocrine gland: have ducts.
• Feedback mechanism regulates hormone release.

Importance of Hormones

• Blood sugar levels increase: pancreas produces more insulin in the blood
• Plant Auxins promote cell enlargement,
• Cytokinins promote cell division in fruits and seeds. Gibberellins help in growth. Abscisic acid inhibits growth.
• Bending of plant occurs when light comes on one side, auxin diffuses to shady side, cells grow longer away from light, so plant bends.

Animal Reproduction

• Reproduction is the process by which organisms produce new individuals of the same species.
• Variation ensures continuity of the species
• Variation helps species adapt and the Variations provide stability to a species while improving the chance of survival.

Asexual Reproduction

• Single parent, no gamete formation, no fertilization, and is genetically similar.
• Fission unicellular organism (splitting of cells): Binary Fission in Amoeba or Leishmania - splitting of cells which produces new cell.
• Fragmentation multicellular Pieces grow into new individuals such as in spirogyra.
• Regeneration if the individual is cut with cells regenerate specialized cells. such as in Hydra and planaria
• Budding develops into ting individuals such as in Hydra, yeast
• Vegetation, Parts like roots, stems, and are genetically is similar.

Sexual Reproduction

• Two parents are, gamete formation fertilization occurs.
• Flowering plants have :
• Pollunation male transferred
• Stament: male
• Pistil: Female

Male vs Female sex traits

• unisexual vs Bisexual has both sex traits.
• Sperm unites with female gamete in humans, puberty, and adolescence

Reproductive health includes contraceptives examples

• Physical Barrier: uses condoms to protect against STD
• Surgical barrier: Surgical for the females