Life Processes: Biology Lecture

Introduction to Life Processes

• A comprehensive lecture on Life Processes will cover the entire chapter within two hours.
• After this lecture, students shouldn't need to consult any other resources on the topic.
• This is the first biology lecture on the presenter's YouTube channel.
• The goal is to make students fully understand the chapter.

What are Life Processes?

• Life Processes are the essential activities necessary for sustaining life.
• They are fundamental functions performed by living organisms to maintain life on Earth.
• Includes nutrition, respiration, transportation, and excretion.
• Nutrition: Consuming food.
• Respiration: Breaking down the food in form of glucose.
• Transportation: Distributing nutrients.
• Excretion: Removal of waste.

Types of Organisms

• Organisms are divided into unicellular and multicellular.
• Unicellular organisms have a single cell, like Amoeba.
• Multicellular organisms have many cells, like humans and plants.

Nutrition: The Essentials

• Nutrition definition: the process by which living organisms obtain and utilize their food.
• Essential for energy, growth, development, and repair of damaged tissues.

Types of Nutrition

• Two main types: autotrophic and heterotrophic.
• Autotrophic organisms make their own food.
• Heterotrophic organisms depend on others for food.

Autotrophic Nutrition: Types

• Two subtypes of autotrophic nutrition:
  • Photosynthetic, using photosynthesis.
  • Chemosynthetic, using chemicals to create energy.

Chemosynthetic Autotrophic Nutrition

• Organisms use chemicals to generate energy, rather than relying on other organisms.
• Chemical energy becomes the organism's food source.
• Example: Sulfur bacteria.

Photosynthetic Nutrition: Ingredients

• Four essential ingredients: carbon dioxide, water, sunlight, and chlorophyll.

Photosynthesis: Process

• Plants take in carbon dioxide through stomata in their leaves.
• Chlorophyll within the leaves captures sunlight.
• Water is also necessary.
• Together, these produce glucose (C6H12O6), water molecules, and oxygen.
• Plants store glucose as starch.
• Animals store glucose as glycogen.

Photosynthesis Reaction

• Absorption of light energy by chlorophyll
• Conversion of light energy to chemical energy
• Splitting of water molecules into hydrogen and oxygen
• Reduction of carbon dioxide to carbohydrates

Stomata: The Exchange Point

• Stomata on leaves facilitate the exchange of gases.
• Stomata have two primary features:
  • Transportation.
  • Exchange of gases during photosynthesis.
  • Transportation: the removal of excess water in the form of vapor.

Stomata: Opening and Closing

• Stomata are surrounded by epidermal cells and guard cells.
• Guard cells regulate the opening and closing.
• When water enters guard cells, the stomata open.
• When water exits guard cells, the stomata close.

Desert Plants: Special Adaptations

• Desert plants capture sunlight and converts in chemical energy.
• Desert plants keeps stomatal pores closed during sunny daytime to avoid water loss.
• They open their pores at night to take in carbon dioxide.
• Photosynthesis process occurs at night.

Heterotrophic Nutrition: Types

• Holozoic: Organisms ingest solid food, then digests and absorbs.
• Saprotrophic: Organisms digest food externally before absorbing nutrients.
  • Includes organisms such as bacteria and fungi.
• Parasitic: Organisms get food from other living organisms.
  • Example: Lice.

Parasitic plant example

• Cuscuta is a plant that doesn't have chlorophyll.
• The plant must perform parasitic nutrition.

Nutrition Utilization

• The cycle of food intake
• Five steps:
  • Ingestion
  • Digestion
  • Absorption
  • Assimilation
  • Egestion

Nutrition Utilization: Amoeba

• Organisms like Amoeba follow same steps as above, from ingestion to egestion.
• It uses a process involving food particles, vacuoles, and enzymes.

Nutrition in Humans: Two Components

• The digestive system has two divisions:
  • The alimentary canal.
  • Associated organs

Alimentary Canal

• The organs where actual food passes when digested such as: mouth, esophagus, stomach, small intestine, and large intestine.

Associated Organs

• Organs where the food does not pass through but contribute to digestion through secretions.
• Organs such as pancreas and liver.

Human Nutrition: Step-by-Step

• Mouth: teeth crush food, mixing with saliva.
• Saliva converts complex sugars to maltose using amylase.
• Esophagus: Food is pushed downward.
• Esophagus happens via involuntary movements caused by rhythmic contraction and relaxation in the muscles.
• Stomach: Hydrochloric acid (kills bacteria and breaks down food).
• Pepsin digests proteins.
• Mucus: Protects stomach lining.

Issues with fast foods

• Eating fast foods result in higher hydrochloric acid secretions.
• Inbalance of mucus and acid leads to acidity.

Liver and Pancreas role

• Liver: secretes bile juice stored in gallbladder.
• Bile juice makes food alkaline(basic), emulsifies fats (breakdown of big fats).
• Pancreas: secretes enzymes.
• Pancreas secrete three enzymes.
• Trypsin helps with the digestion of proteins.
• Lipase helps breakdown emulsified fats.
• Pancreatic amylase helps with digestion of carbohydrates.

Small Intestine

• Aids in food digestion.
• 5-7 meters long.
• Creates intestinal juices.
• Intestinal juices helps final breakdown of left over foods.
• Enzymes like maltase, sucrase, lactase, and lipase contribute to the process.

Small Intestine Digestion

• Absorption occurs in the villi.
• Absorption happens with many blood vessels inside villi.
• Structure of villi facilitates the absorption of broken down products into blood capillaries.
• Villi structures has finger like projections. Helps increase surface area for food absorption

Large Intestine

• Waste get passed here.
• Water in the undigested materials are absorbed.
• Solid waste then removed through the anus.

Key Points

• Importance of liver and pancreas secretions.
• Bile helps neutralize acid and simplify fats.
• Pancreatic enzymes assists digestion of proteins, fats and carbs.
• Small intestine villi aids nutrient absorption.

Conclusion of the nutrition process

• By following all these steps, we can properly digest and get the nutrients out of our food. Now, where did those undigested waste go?

Reminder

• Need to digest cellulose since their diet consists mainly of plants.
• Longer intestines are required for complete digestion.

Respiration

• Definition: The process by which living organisms obtain ATP (energy)
• Involves breaking down glucose (sugar) to release energy.
• Formula:
  • Glucose+Oxygen=Carbon Dioxide+Water+Energy

Differentiation of breathing and respiration

• Breathing and respiration are different.
• Breathing: Physical inhalation and exhalation of air.
• Respiration: Chemical process of releasing energy from food.
• Breathing is part of respiration.

Different Type of Respiration

• Aerobic respiration requires oxygen.
• Anaerobic: Doesn't requires oxygen.

Cellular Activities

• All those above reactions happen inside cell.
• Takes place inside cytoplasm and mitochondria.
• Glucose breaks down into pyruvate inside cytoplasm.
• Break down of pyruvate in mitochondria needs oxygen to create carbon dioxide, water and ATP(energy).
• If no oxygen in animals, the break down of pyruvate produces lactic acid and energy resulting in cramps.
• In yeast, it breaks into ethanol, carbon dioxide and energy.

Gas Exchange in Plants

• Gas exchange occurs in stomato.

Respiration in Humans: Air Flow

-Human respiration involves several organs starting with the nasal cavity -> pharynx -> larynx (voice box) -> trachea (or windpipe) which then branches into the lungs forming bronchi, bronchioles that culminates in alveoli (air sacs).

What are alveoli?

• Air sacs structure used to transmit oxygen and carbon dioxide.
• In alveoli, deoxygenated blood exchanges carbon dioxide for oxygen.
• Blood cells have hemoglobin for transporting the gases.

Exchange of Gases with Alveoli

• Alveoli is balloon-like.
• It is single-layered.
• Contains a network of blood vessels.
• Process aids gas exchange.

Respiration in Fish

• Fish uses gills instead of lungs.
• Gills extract oxygen from water.
• Rate of breeding is faster since oxygen is limited inside water.

Transportation

• Definition: transport of substances.
• Transports substances in body.
• Circulatory system is made of blood, vessels, heart.

Blood

• Has plasma, and corpuscles.
• Corpuscles are RBC, WBC, platelets.
• BLC contains important component called hemoglobin that helps deliver oxygen.
• WBC protects by fighting infections.
• Platelets aid blood clotting.

Functions of Blood

• Deliver nutrients, hormones, and oxygen to cells.
• Carries away carbon dioxide.
• Maintains body temperature and Ph balance.

Blood Vessels

• They move blood throughout the body.
• Has arteries, veins, and capillaries.
• Arteries carry blood away from the heart.
• Veins back to the heart.
• Capillaries connect veins and arteries.

Arteries Versus Veins

• Arteries has strong thick walls to deal with high pressure.
• Veins thin for less pressure.
• Pulmonary Artery carries deoxygenated blood.
• Pulmonary Veins carries oxygenated blood.
• Veins has valves to prevent back flow of blood.
• Arteries's pressure is higher.
• Low pressure in veins.

Understanding Blood Flow Direction

• In arteries it's away and veins it's toward heart.
• Arteries contains high blood pressure and has thick walls.

Chambers of the Heart

• Consists of 4 chambers.
• Two superior atria and two inferior ventricles.
• Oxygenated blood flows through the left side and deoxygenated on the right.
• Divided with two circuits:pulmonary/systemic.

Two Circuits

• Systemic: heart pumps oxygenated blood out to body from left side of the heart and returns deoxygenated blood back.
• Pulmonary: moves blood between heart and lungs for oxygenation from right side the heart.

Step-by-step Process of the heart

• Lungs > pulmonary vein > left atrium > left ventricle.

Vessels

• Blood is then pushed out to all body by the aorta and then becomes deoxygentated.
• Deoxygenated returns to right atrium via vena cava.
• From the right atrium it goes to right ventricle.
• Finally, blood gets sent it sends deoxygenated blood to the lungs via the pulmonary aftery.

Double Circulation

• Humans have double circulations since blood travels across the heart twice.
• Blood has to travel lungs and rest of body.

Hearts Need Chambers

• More efficient system.
• Supplies more oxygen to organs.
• Has high efficient oxygen supply which creates energy.

Lymphatic System

• Some schools do not teach.
• Made of lymph fluid lymph vessels, lymph nodes.
• Essential for: Fluid balance, Fats transprt, immune system.

System Significance

• Maintains fluid balance and facilitates system for transportation with the immune function.
• Transport fats.
• Protect due to its immune system.

Transportation in Plants

• Involves both xylem and pholem.
• Xylem: transfer water from roots of plant to the leaves.
• Pholem transfer food generated in leaves all thru the plant.

Difference Between Xylem and Pholem

• Flow varies from uni-directional to multi.
• Composed of dead and living material.

Transportation

• This enables water absorption as well temperature pressure.
• Getting rid fo the water.
• Essential for regulating temperature and maintaining moisture during transportion.
• This helps in temp relation.

Excretion

• Definition: Processes to release waste.
• Different in the process of elimination solids.
• In urine it goes through a number of processes to eliminate waste. Function and system:
• Two kidneys.
• The bladder in the ureter.
• Kidneys in system used to filtrate/separate waste and water for extraction.
• Urine storage in bladder through urethra.
• Functions.
• Excrete the waste, maintains PH and makes hormones.
• Regulates blood pressure.

Nephron

• Nephron is inside Kidneys.
• Important part of Kidney, millions are in Kidneys.
• Working can dictate if system is ok.
• Blood vessels from glomereulus to bowman capsule to purify.
• To re-absorb material in tubular secreation.
• Ex. Waste extra salt.
• Processes.
• Glomerular filtrations-
• Selective reabsorption.
• Tubular Secretion.

Dialysis

• Process where Blood is artificially purified when kidneys fail.
• Blood removed from body, filtered mechanically, returned.
• Machine cleans blood than blood return to patients.

Other notes, how plans

• Plants gets different strategies to rid of water.
• Through transpiration stomas.
• Waste products stored in cellular vacuoles.