Cellular Respiration & Photosynthesis: Processes & Cycles
Cellular Respiration
Role in Cellular Respiration
- Glucose: This organic molecule is oxidized (loses H+) in the presence of oxygen to CO2 and H2O.
- Oxygen: The final electron acceptor and proton recipient, it reduces to H2O.
- NAD+ and FAD: Coenzymes that capture the H+ lost during the oxidation of organic molecules like glucose. These are reduced to NADH + H+ and FADH2, respectively. Subsequently, these reduced coenzymes yield hydrogen to oxygen.
- Electron Transport Proteins: Protein molecules located in
Structure and Function of Nucleic Acids: DNA, RNA, and Proteins
Structure of Nucleotides and Nucleosides
A nucleoside consists of a nitrogenous base (purine or pyrimidine) covalently linked to a five-carbon sugar (pentose, either ribose or deoxyribose) via an N-glycosidic bond. Examples of nucleosides include cytidine, uridine, adenosine, guanosine, thymidine, and inosine. Nucleosides can combine with a phosphate group (phosphoric acid: H3PO4) through the action of kinases, producing nucleotides, which are the basic building blocks of DNA and RNA molecules.
Nucleotide
Read MoreGametogenesis: Sperm and Egg Formation Explained
Gametogenesis
Gametogenesis is the formation of gametes (sex cells) from germ cells through meiosis. This process reduces the chromosome number in germ cells from diploid (double) to haploid (single), meaning half the number of chromosomes found in a normal cell of the species. In humans, the process that produces sperm is called spermatogenesis and occurs in the testes. The process that produces eggs is called oogenesis and occurs in the ovaries.
Gametogenesis involves two chromosomal and cytoplasmic
Read MoreExploring the Cell: A Comprehensive Guide to Organelles and Their Functions
Plasma Membrane
Characteristics
The plasma membrane consists of a lipid bilayer with proteins embedded within or attached to its surfaces.
Functions
The plasma membrane controls the entry and exit of substances, both qualitatively and quantitatively. This selective permeability allows the passage of small solvents and solutes while restricting larger ones. This process helps determine the cytoplasm’s composition through nutrient uptake and waste excretion.
Golgi Apparatus
Characteristics
The Golgi apparatus
Read MoreRespiratory System: Breathing Process and Common Diseases
Breathing
Breathing is the process of taking in oxygen from the air and transporting it to the cells, where it’s used in chemical reactions to produce energy. These reactions generate carbon dioxide, which is expelled during exhalation.
Breathing involves two phases:
- External Respiration: Oxygen moves from the air into the blood, and carbon dioxide moves from the blood into the air in the lungs.
- Internal Respiration: Oxygen travels through the blood to body cells for energy production. Carbon dioxide
Understanding Ecosystems: Energy Flow, Matter Cycles, and Human Impact
Matter and Energy in Ecosystems
Ecosystems are dynamic, complex natural systems where living organisms interact with their environment. Examples include ponds, deserts, and forests.
Types of Living Organisms
Living organisms need organic matter to build their bodies and as fuel. They are classified based on how they obtain organic matter:
- Autotrophs: Synthesize organic material from inorganic molecules using sunlight (e.g., plants and algae).
- Heterotrophs: Obtain organic matter from other organisms (