Unit 1 Topic 2: Exchange of nutrients and wastes Flashcards
What is the function of carbohydrates
Carbohydrates provide energy, support cell structure, and play a role in cell signaling.
✨ Key Role: Main source of energy and essential for cell communication.
What is the function of proteins
Proteins are essential for structure, enzymatic reactions, transport, signaling, and defense in cells.
✨ Key Role: Build and repair tissues, regulate processes, and enable cell function.
What is the function of lipids
Lipids store energy, form cell membranes, and provide insulation and protection.
✨ Key Role: Long-term energy storage and structural component of cell membranes.
What is the role of amylase in chemical digestion
Amylase is an enzyme that breaks down starch into simple sugars (maltose) during digestion. It is found in saliva and the pancreas.
✨ Key Role: Speeds up starch digestion into sugars for energy.
What is the role of protease in chemical digestion
Protease is an enzyme that breaks down proteins into amino acids. It is found in the stomach (pepsin), pancreas, and small intestine.
✨ Key Role: Helps digest proteins for growth and repair.
What is the role of lipase in chemical digestion
Lipase is an enzyme that breaks down lipids (fats) into glycerol and fatty acids. It is produced by the pancreas and works in the small intestine.
✨ Key Role: Aids in fat digestion for energy and cell function.
Explain how structural features of exchange surfaces in the digestive systems of mammals allow for efficient nutrient exchange.
Digestive System:
Villi and Microvilli: The inner surface of the small intestine has villi covered with microvilli, increasing surface area for absorption.
Thin Epithelium: The thin cell layer of villi allows nutrients to easily diffuse from the gut into the blood.
Rich Blood Supply: A dense network of capillaries transports absorbed nutrients away, maintaining a concentration gradient.
✨ Key Role: These features maximize nutrient absorption into the bloodstream.
Describe how closed circulatory systems facilitate the efficient transport of materials to and from all cells in the body.
In a closed circulatory system, blood circulates within blood vessels, ensuring efficient transport of materials to and from all cells.
Key Features:
Blood Vessels: Blood is confined to arteries, veins, and capillaries, allowing for controlled and directed flow.
Heart: The heart pumps blood under pressure, ensuring rapid and continuous flow through the system.
Capillaries: These tiny, thin-walled vessels allow efficient exchange of gases, nutrients, and waste between the blood and tissues.
Two Circuits:
Pulmonary Circuit: Blood flows to the lungs for gas exchange (oxygen in, carbon dioxide out).
Systemic Circuit: Oxygenated blood is delivered to the rest of the body.
✨ Key Role: The closed system maintains high pressure, ensuring quick delivery of oxygen, nutrients, and removal of waste to all cells, supporting efficient cellular functions.
Explain how glomerular filtration, selective reabsorption and secretion across nephron membranes contribute to the removal of waste.
- Glomerular Filtration: Filters out waste and excess substances from the blood.
- Selective reabsorption: Prevents loss of important nutrients and maintains fluid balance.
- Secretion: Further removes unwanted substances from the blood.
Explain how metabolic processes, such as digestion, are controlled and regulated by enzymes.
Enzymes regulate and speed up digestion, ensuring that nutrients are broken down efficiently and absorbed at the right time, and that waste products are eliminated.
Describe the structure and function of enzymes, including the role of the active site.
The active site binds to the substrate and forms an enzyme-substrate complex. This allows the enzyme to catalyze the conversion of substrates into products. After the reaction, the products are released, and the enzyme is free to catalyze more reactions.
Explain how enzyme activity is affected by factors such as temperature, pH, presence of inhibitors and substrate concentration.
Temperature:
Temperature affects the rate of reaction and the enzyme’s shape.
pH:
pH affects the enzyme’s structure and activity, ensuring they work in the right environment.
Presence of Inhibitors:
Inhibitors regulate enzyme activity by preventing or reducing substrate binding.
Substrate Concentration:
Substrate concentration determines the rate at which enzymes can process reactions.
What are enzymes
Enzymes are proteins that act as biological catalysts, significantly accelerating chemical reactions within the body. They are essential for various physiological processes, including digestion, energy production, and metabolism.
Explain how structural features of exchange surfaces in the circulatory systems of mammals allow for efficient nutrient exchange.
Circulatory System:
Capillaries: Thin-walled and one cell thick, allowing rapid exchange of gases, nutrients, and waste products.
Large Surface Area: The network of capillaries provides a large surface area for diffusion.
Blood Flow: Blood is pumped efficiently to maintain concentration gradients for exchange.
