Life Processes: Nutrition and Respiration

Life Processes

Nutrition

• Autotrophic nutrition: organisms produce their own food using sunlight, water, and carbon dioxide (e.g., plants)
• Heterotrophic nutrition: organisms obtain food by consuming other organisms or organic matter (e.g., animals, fungi)
• Holozoic nutrition: organisms ingest solid food particles (e.g., animals)
• Saprotrophic nutrition: organisms obtain food by breaking down dead organic matter (e.g., fungi)

Respiration

• Cellular respiration: process of generating energy from glucose in the presence of oxygen (aerobic respiration) or absence of oxygen (anaerobic respiration)
• Aerobic respiration: glucose + oxygen → carbon dioxide + water + energy (ATP)
• Anaerobic respiration: glucose → lactic acid + energy (ATP)

Transportation

• Transportation in plants: movement of water, minerals, and nutrients from roots to leaves through xylem and phloem
• Transportation in animals: movement of oxygen, nutrients, and waste products through blood circulation

Excretion

• Removal of waste products from the body
• Excretory organs: kidneys, liver, skin, and lungs

Regulation and Control

• Homeostasis: maintenance of a stable internal environment despite changes in external conditions
• Feedback mechanisms: negative feedback (reverses change) and positive feedback (amplifies change)

Growth and Development

• Growth: increase in size and mass
• Development: series of changes that occur in an organism from fertilization to maturity
• Factors influencing growth and development: hormones, nutrition, and genetics

Life Processes

Nutrition

• Autotrophic nutrition involves producing food using sunlight, water, and carbon dioxide, exemplified by plants.
• Heterotrophic nutrition involves obtaining food by consuming other organisms or organic matter, seen in animals and fungi.
• Holozoic nutrition is characterized by ingesting solid food particles, a trait found in animals.
• Saprotrophic nutrition involves breaking down dead organic matter to obtain food, a process used by fungi.

Respiration

• Cellular respiration is the process of generating energy from glucose, which can occur in the presence of oxygen (aerobic respiration) or absence of oxygen (anaerobic respiration).
• Aerobic respiration converts glucose and oxygen into carbon dioxide, water, and energy (ATP).
• Anaerobic respiration converts glucose into lactic acid and energy (ATP).

Transportation

• In plants, transportation involves the movement of water, minerals, and nutrients from roots to leaves through the xylem and phloem.
• In animals, transportation occurs through blood circulation, which moves oxygen, nutrients, and waste products throughout the body.

Excretion

• Excretion is the process of removing waste products from the body.
• The kidneys, liver, skin, and lungs are excretory organs that facilitate this process.

Regulation and Control

• Homeostasis is the maintenance of a stable internal environment despite changes in external conditions.
• Feedback mechanisms, including negative and positive feedback, help regulate and control various bodily functions.

Growth and Development

• Growth is defined as an increase in size and mass.
• Development is a series of changes that occur in an organism from fertilization to maturity.
• Factors influencing growth and development include hormones, nutrition, and genetics.

Learn about the different modes of nutrition including autotrophic, heterotrophic, holozoic, and saprotrophic nutrition. Also, understand the process of cellular respiration.