Biology: Nutrition and Respiration

Study Notes

Autotrophic nutrition: Plants, algae, and some bacteria make their own food through photosynthesis, using sunlight, water, and CO2.
Heterotrophic nutrition: Animals, fungi, and some bacteria obtain energy by consuming other organisms or organic matter.

Aerobic respiration: Cellular respiration that occurs in the presence of oxygen (O2), producing energy (ATP) and water (H2O) as byproducts.
Anaerobic respiration: Cellular respiration that occurs in the absence of oxygen (O2), producing energy (ATP) and lactic acid or ethanol as byproducts.

** Circulatory system**: Heart, blood vessels, and blood work together to transport oxygen, nutrients, and waste products throughout the body.
Transport mechanisms:
- Passive transport: Diffusion, osmosis, and facilitated diffusion allow molecules to move across cell membranes without energy expenditure.
- Active transport: Energy-dependent processes, such as carrier proteins and pumps, move molecules across cell membranes against their concentration gradient.

Excretory organs: Kidneys, liver, lungs, and skin remove waste products from the body.
Excretory processes:
- Filtration: Waste products are filtered from the blood by the kidneys.
- Reabsorption: Essential nutrients and water are reabsorbed into the bloodstream.
- Secretion: Waste products are secreted into the urine.

Nervous system: Central nervous system (brain and spinal cord) and peripheral nervous system (nerves) work together to coordinate body functions.
Hormonal control: Endocrine glands produce hormones that regulate various physiological processes, such as growth and development.

Asexual reproduction: Single parent produces genetically identical offspring, e.g., binary fission in bacteria.
Sexual reproduction: Two parents produce genetically unique offspring, e.g., meiosis in animals and plants.

Plants, algae, and some bacteria make their own food through photosynthesis, using sunlight, water, and CO2.
Animals, fungi, and some bacteria obtain energy by consuming other organisms or organic matter.

Aerobic respiration occurs in the presence of oxygen (O2), producing energy (ATP) and water (H2O) as byproducts.
Anaerobic respiration occurs in the absence of oxygen (O2), producing energy (ATP) and lactic acid or ethanol as byproducts.

The heart, blood vessels, and blood work together to transport oxygen, nutrients, and waste products throughout the body.
Diffusion, osmosis, and facilitated diffusion allow molecules to move across cell membranes without energy expenditure.
Carrier proteins and pumps move molecules across cell membranes against their concentration gradient, requiring energy.

The kidneys, liver, lungs, and skin remove waste products from the body.
Filtration removes waste products from the blood by the kidneys.
Reabsorption reabsorbs essential nutrients and water into the bloodstream.
Secretion secretes waste products into the urine.

The central nervous system (brain and spinal cord) and peripheral nervous system (nerves) work together to coordinate body functions.
Endocrine glands produce hormones that regulate various physiological processes, such as growth and development.

Asexual reproduction produces genetically identical offspring, e.g., binary fission in bacteria.
Sexual reproduction produces genetically unique offspring, e.g., meiosis in animals and plants.