Life Processes: Maintaining Life

Life Processes

• Living beings can be identified by observing activities such as running, chewing cud (cows), or shouting, and breathing.
• Growth and movement are generally perceived as indicators of life.
• Molecular movement, though invisible, is crucial for life
• Viruses exemplify the debate around life, as they show no molecular movement until they infect a cell.
• Living organisms maintain well-organized structures.
• Repair and maintenance are essential to counteract environmental effects.
• Molecular movement is constant to maintain these structures.

What are Life Processes?

• Maintenance functions are continuous, even during inactivity or sleep.
• Life processes encompass all maintenance functions.
• Energy is essential to prevent damage and breakdown to carry out life processes.
• Nutrition is the process of obtaining energy (food) from outside the body.
• Additional raw materials are required for growth from outside like carbon-based molecules.
• Organisms use varied nutritional processes according to the complexity of the carbon sources.
• Energy sources must be broken down or built up into a uniform energy source usable for molecular movements and growth.
• Chemical reactions, like oxidizing-reducing reactions, are essential for breaking down molecules
• Respiration involves acquiring oxygen to break down food for cellular needs.
• Single-celled organisms do not require specific organs for food intake, gas exchange, or waste removal due to direct contact with the environment.
• Multi-cellular organisms require specialized tissues for these functions as simple diffusion is not sufficient.
• A transportation system is needed to carry food and oxygen to all parts of the body.
• Excretion is the process where waste by-products from used carbon and oxygen are removed and discarded.
• Specialized tissues and transportation systems are essential for excretion in multi-cellular organisms.

Nutrition

• Nutrition is essential to provide energy for various activities like walking or riding a bicycle.
• Energy is also crucial for maintaining order in the body even when not actively doing anything.
• Food provides energy and materials for growth, development, and synthesis within the body from external sources.
• All organisms need energy and materials, but they get them in different ways.
• Autotrophs use simple food material from inorganic sources like carbon dioxide and water, and include green plants and some bacteria.
• Heterotrophs utilize complex substances that must be broken down into simpler ones using enzymes.
• Heterotrophs depend on autotrophs directly or indirectly.
• Animals and fungi are examples of heterotrophic organisms.

Autotrophic Nutrition

• Photosynthesis satisfies carbon and energy requirements in autotrophs.
• Autotrophs take in and convert external substances into stored energy forms
• Chlorophyll converts carbon dioxide and water into carbohydrates using sunlight and chlorophyll.
• Carbohydrates are then used for energy.
• Unused carbohydrates are stored as starch to be available for future use by the plant.
• Energy derived from food is stored as glycogen in humans.
• Photosynthesis involves specific events
• Chlorophyll absorbs light energy
• Light energy converts into chemical energy, splitting water into hydrogen and oxygen
• Carbon dioxide reduces into carbohydrates
• These steps don't need to happen right away one after another.
• Desert plants take CO2 at night and use energy absorbed during the day
• Some cells are containing green dots called Chloroplasts containing chlorophyll.

Activity 5.1

• Variegated leaves remove starch by placing in a dark room for three days
• Plant left in sunlight for six hours
• Green areas of leaf are marked on paper
• Leaf dipped in boiling water and alcohol
• Alcohol beaker placed in water bath until it boils
• Leaf dipped in a dilute iodine solution and rinsed
• Leaf color is compared to green marks on paper
• Presence of starch can be determined for areas of the leaf

Plant Gas Exchange

• Stomata are tiny pores on the leaf surfaces.
• Gas exchange for photosynthesis occurs through these stomata on leaves, stems, and roots.
• Stomata close to prevent water loss when carbon dioxide is not needed for photosynthesis.
• Guard cells control the opening and closing of stomatal pores.
• Stomatal pores open when guard cells swell with water intake.
• Stomatal pores close when guard cells shrink.

Activity 5.2

• Two sample potted plants with nearly the same size
• Both pots placed in a dark room for 3 days
• Potassium hydroxide is used to absorb carbon dioxide, and placed in Potassium hydroxide's watch glass
• Both plants are covered with a bell jar, sealed with Vaseline
• Plants placed in sunlight for two hours
• Plucking a leaf and checking starch is preformed
• Leaves are checked for similar starch
• Conclusion stated

Autotroph Energy needs

• For autotrophs water is taken from soil through roots in Terrestrial plants for photosynthesis
• N, P, Iron, Mg are taken from soil.
• N is essential for synthesis of proteins or other compounds.

Heterotrophic Nutrition

• Organisms adapt to their environment
• Type and availability of food differ based on source
• How food is obtained impacts nutritive apparatus in lion vs cow
• Some organisms break down food outside their bodies then absorb it ie fungi/mushrooms
• Body design and functioning impacts absorption, where they will take nutrients from.
• Parasitic feeding strategy consists of org taking nutrients from host ex) ticks/leeches

How Organisms Obtain Nutrition

• Digestion and digestive systems vary across organisms due to differences in food and how it's obtained
• Single-celled organism food may be taken in by entire surface
• As complexity increases, parts specialize for different functions
  • Amoeba takes in food, forms a food vacuole
  • Complex substances broken down into simple ones and into cytoplasm
  • Undigested material goes to cell surface and it is thrown out
  • Paramoecium also singular but takes food in specific spot. Move food via cilia.

Human Nutrition

• Alimentary canal is a long tube from the mouth to the anus.
• Tube has different parts.
• Regions specialize in different functions.
• Processing generates small particles
• Texture of lining is soft, food wetted for smoother process
• Saliva fluids are secreted by salivary glands and helps digestion
• Complex nature of food is broken to release smaller molecules by enzymes or biological catalysts
• Saliva breaks starch in amylase
• Food mixed with saliva and mouth thoroughly mixed by muscular tongue.

Moving Food

• It is necessary to move food in a regulated manner
• Muscles of canal contract rhythmically to push food
• Process occurs along gut with peristaltic movement
• From mouth->stomach via esophogus
• Stomach large organ expands
• Muscular walls mix food and digestive juices.
• Gastric glands care for digestion inside stomach
• Hydrochloric acid and pepsin protein help in digestion
• Acidic medium facilitates pepsin action
• Mucus protects lining of stomach.
• Sphincter muscle regulates food from releasing acids and enters intestinal
• Small intestine longest part of canal fits small space due to coiling
• Herb, carnivore intestine length depend of length of digestion
• Completes digestion of carbs, fats, protein. Receives secretion from liver an pancreas
• Food has to be alkaline for pancreatic to operate
• Bile juice acts on fat from liver.
• Fats are large globules and enzymes act.
• Breaks down small globules to increase efficiency.
• Action similar to soap like chapter 4.

Pancreas

• Pancreas: secretes pancreatic juice.
• Trypsin (Protein digesting enzymes).
• Lipase/emulsified fats.
• Walls of intestine has glands which intestine contains juice.
• The enzymes break down proteins, carbs etc.
• Intestine walls absorb digestion. Inner lining of projections called villi increases surface
• Vili have blood vessels which deliver and transfer the food and energy to cells.
• Body can use those nutrients for structure, and maintenance.
• Undigested to large intestine, absorb water
• Rest to Anus and anal sphincter to exit body

Dental Caries

• Tooth decay causes softening of enamel and dentine.
• Bacteria creates acids that softens enamel
• Masses of bacterial cells stick with partickes to create plaque
• Plaque stops saliva to neutralize acids.
• Untreated org may lead to infection.

Respiration

• Nutrition has been discussed
• Food is used in cells to provide energy for processes
• Diverse ways org use oxygen.
• First breakdown glucose, 6C molec and into 3C molec
• Pyruvate occurs after that, broken down further.

Respiration Activity

• Mix fruit juice/sugar with yeast
• Added to test tube c 1-holed cork
• Cork corked with bent glass. Free end with lime water
• What occurs.
• Discuss what products fermentation.
• Break three carbon pyruvate into three of carbon dioxide using the process of cellular respiration
• Aerobic. Process lots greater than in anaerobic
• When lack oxygen in cells, path for breaking pyru takes place, pyru turns to lactic acid
• This causes cramps.

Aerobic and Anaerobic

• The Aerobic (Using oxygen) turns three carbon pyru molec to CO2
• Much more is released than anaerobic
• Lack of oxygen in cells, pyru turns to lactic acid and causes cramp.

ATP

• Energy stored comes from respiration molecules.
• ATP is energy currency.
• ATP breaks down in endothermic. releases energy equivalents .
• ATP similar battery energy. muscles synthesis etc

Aerobic

• Aerobic (using oxygen) pathways dependent on air/oxygen.
• Plants exchange gas via stomata
• intercellular space ensures contact cells air
• Carbon goes in.
• Direction of diffusion depends on environment, needs of plant.
• CO2 elimination goes.
• Oxygen major at time

Animal Respiration

• Different organs to obtain oxygen to produce carbon dioxide
• Animals living depend on water. Have to depend to dissolve

Fish Respiration Activity

• Open gills coordinated open mouth when fish
• Timing
• Comparison