Biology notes not covered Flashcards
What is the difference in fermentation pathways between animals and plants?
In animals, pyruvate is converted to lactate. In plant and yeast cells, pyruvate is converted to ethanol and carbon dioxide.
How many molecules of ATP are produced by fermentation in both plants and animals?
Fermentation pathways in both plants and animals only produce the initial two molecules of ATP.
Where does fermentation occur?
Fermentation occurs in the cytoplasm.
Where does aerobic respiration start and finish?
Aerobic respiration starts in the cytoplasm and is completed inside the mitochondria.
What is the word equation for aerobic respiration?
Glucose + Oxygen → Carbon Dioxide + Water + Energy
What is the word equation for fermentation in animals?
Glucose → Lactic Acid + Energy
What is the word equation for fermentation in plants?
Glucose → Ethanol + Carbon Dioxide + Energy
What happens to each pyruvate in aerobic respiration?
Each pyruvate is broken down to carbon dioxide and water, yielding a large number of ATP molecules.
What is the outcome of glucose breakdown in both aerobic respiration and fermentation?
Glucose is broken down to two molecules of pyruvate, yielding two molecules of ATP.
What does the further breakdown of pyruvate depend on?
The presence or absence of oxygen.
What is respiration?
Respiration is when the chemical energy stored in glucose is released by all cells through a series of enzyme-controlled reactions.
Which cells contain a high number of mitochondria?
Muscle Cells: Muscle cells, especially those in skeletal muscles, require a lot of energy for contraction, so they have many mitochondria to produce ATP.
Sperm Cells: Sperm cells need energy for movement, particularly for the flagellum (tail) to swim, so they contain numerous mitochondria.
Neurone Cells: Neurons require a lot of energy to transmit electrical impulses and maintain ion gradients, so they have many mitochondria to support these processes.
How is ATP generated from glucose breakdown?
The energy released from the breakdown of glucose is used to generate ATP from ADP and phosphate.
How can genetic information be transferred between cells?
Genetic information can be transferred from one cell to another by genetic engineering.
Give examples of two enzymes their specific substrate and the product of the reaction.
Amylase:
Substrate: Starch
Product: Maltose (a sugar)
Reaction: Amylase breaks down starch into smaller sugar units (maltose) during digestion.
Lipase:
Substrate: Lipids (fats)
Product: Fatty acids and glycerol
Reaction: Lipase breaks down lipids into fatty acids and glycerol, aiding in fat digestion.
What is the result of enzyme action?
Enzyme action results in product/products.
What is the role of Messenger RNA (mRNA)?
mRNA carries a copy of the code from the DNA in the nucleus to a ribosome, where the protein is assembled from amino acids.
What contributes to the variety of protein shapes and functions?
The sequence of amino acids contributes to the variety of protein shapes and functions.
Give examples of the various functions of proteins: - to include structural, enzymes, hormones, antibodies and receptors.
Structural: Collagen provides strength and structure to connective tissues like skin and tendons.
Enzymes: Amylase helps break down starch into sugar during digestion.
Hormones: Insulin regulates blood sugar levels.
Antibodies: Immunoglobulins (like IgG) fight infections by binding to pathogens.
Receptors: Insulin receptors on cell membranes detect insulin and trigger cellular responses.
Each type of protein plays a crucial role in the body’s functions.
What exists between cells and their environment?
Different concentrations of substances exist between cells and their environment, creating concentration gradients. Substances like oxygen, nutrients, and waste products can move in and out of cells based on these gradients. This difference in concentration is key for processes like diffusion and active transport.
Explain the importance of diffusion to a cell, for substances such as: - glucose, amino acids, oxygen and carbon dioxide.
Diffusion is crucial for cells because it allows substances to move across cell membranes without using energy. Here’s why it’s important for each substance:
Glucose: Diffuses into cells for energy production (cellular respiration).
Amino Acids: Diffuse into cells to be used in protein synthesis.
Oxygen: Diffuses into cells for cellular respiration to produce energy.
Carbon Dioxide: Diffuses out of cells as a waste product of cellular respiration.
Diffusion ensures that cells get essential nutrients and remove waste efficiently.
Give examples of active transport.
Sodium-Potassium Pump (Nerve Cells): In nerve cells, sodium ions are actively pumped out, and potassium ions are pumped in, against their concentration gradients, using energy (ATP). This helps maintain the resting potential and supports nerve impulses.
Iodine in Seaweeds: Seaweeds use active transport to absorb iodine from seawater, even when the iodine concentration is lower outside the cell than inside. This helps them store iodine for metabolic processes.
Describe the structure of an individual villus –identifying blood capillary and lacteal.
An individual villus is a small, finger-like projection in the small intestine, designed to increase surface area for nutrient absorption. Here’s its structure:
Epithelial Cells: These line the villus and have microvilli on their surface, further increasing surface area.
Blood Capillary: A tiny blood vessel inside the villus that absorbs amino acids and sugars (like glucose) from digested food into the bloodstream.
Lacteal: A lymphatic vessel inside the villus that absorbs fatty acids and glycerol (from fats) into the lymphatic system for transport.
The presence of both a blood capillary and a lacteal allows the villus to absorb different types of nutrients efficiently.
State what blood capillary and the lacteal absorbs.
The blood capillary absorbs glucose and amino acids, and the lacteal absorbs fatty acids and glycerol.
Describe the structures of the small intestine that make it efficient at absorption. This should include: large number of thin walled villi provide a large surface area, and a large network of blood capillaries.
The small intestine is highly efficient at absorption due to its specialized structures:
Villi: Tiny, finger-like projections that line the inner surface of the small intestine. The large number of villi significantly increases the surface area available for absorption.
Blood Capillaries: Inside each villus is a network of blood capillaries, which absorbs nutrients such as amino acids and glucose, transporting them into the bloodstream for distribution throughout the body.
Lacteals: Also within each villus is a lacteal (a small lymph vessel) that absorbs fats (fatty acids and glycerol) into the lymphatic system for transport.
These features work together to maximize the efficiency of nutrient absorption in the small intestine.
What is the structure of xylem vessels?
Xylem vessels are hollow tubes supported by rings of lignin.
Why is water required in plants?
Water is required for transporting materials and for photosynthesis.
What are the structures involved in water movement in a plant?
The structures involved are root hairs, xylem, guard cells, stomata, epidermis, and mesophyll cells.
What is transpiration?
Transpiration is the process of water movement through a plant and its evaporation from aerial parts.
What factors affect the rate of transpiration?
The rate of transpiration is affected by wind speed, humidity, temperature, and surface area.
How is sugar transported in plants?
Sugar is transported up and down the plant in living phloem.
What is the structure of phloem?
Phloem consists of a phloem tube separated by sieve plates and companion cells.
Describe how phagocytes and lymphocytes destroy pathogens.
Phagocytes:
Engulfing Pathogens: Phagocytes (like macrophages) find and eat pathogens (such as bacteria) in a process called phagocytosis.
Breaking Down: After the pathogen is engulfed, the phagocyte uses special chemicals to digest and destroy it.
Lymphocytes:
T Lymphocytes (T Cells): T cells attack infected cells directly to destroy the pathogens inside them.
B Lymphocytes (B Cells): B cells make antibodies that stick to the pathogens, marking them so other immune cells can destroy them.
Describe how red blood cells are specialised
Red blood cells are specialised as they are biconcave in shape and have no nucleus (which increases surface area), and contain haemoglobin. This allows them to transport oxygen efficiently in the form of oxyhaemoglobin.
What are the characteristics of arteries?
Arteries have thick muscular walls, a narrow central channel, and carry blood under high pressure away from the heart.
What are the characteristics of veins?
Veins have thinner walls, a wider channel, and carry blood under low pressure back towards the heart.
State the function of the coronary artery.
The coronary artery supplies oxygenated blood to the heart muscle. This is crucial because the heart needs a constant supply of oxygen and nutrients to function effectively and pump blood throughout the body.
What must be absorbed into the bloodstream for respiration?
Oxygen and nutrients from food must be absorbed into the bloodstream to be delivered to cells for respiration.Waste materials, such as carbon dioxide, must be removed from cells into the bloodstream.
What do tissues contain to allow material exchange?
Tissues contain capillary networks to allow the exchange of materials at the cellular level.
What features do surfaces involved in absorption have in common?
Surfaces involved in the absorption of materials have a large surface area, thin walls, and extensive blood supply. These features increase the efficiency of absorption.
What keeps airways open?
Rings of cartilage keep airways open.
What is a species?
A group of organisms that can interbreed and produce fertile offspring.
What is biodiversity?
The variety of different species, genetic variation, and ecosystems within a particular area.
What is a population?
A group of organisms of the same species living in the same area at the same time.
What is a producer?
An organism (like plants or algae) that makes its own food using sunlight, water, and carbon dioxide through photosynthesis.
What is a consumer?
An organism that gets its energy by eating other organisms (plants or animals).
What is an herbivore?
An animal that eats plants.
What is a carnivore?
An animal that eats other animals.
What is an omnivore?
An animal that eats both plants and animals.
What is a predator?
An animal that hunts and kills other animals for food.
What is prey?
An animal that is hunted and eaten by predators.
What is a food chain?
A series of organisms, each dependent on the next as a source of food, starting with a producer.
What is a food web?
A network of interconnected food chains in an ecosystem, showing how energy and nutrients flow through different organisms.
What is an ecosystem?
A community of living organisms interacting with each other and their physical environment (like air, water, and soil). It includes both biotic (living) and abiotic (non-living) components.
How do food webs interact in an ecosystem?
In an ecosystem, multiple food webs exist, as organisms are part of several food chains, interacting in complex ways to transfer energy and nutrients.
What is a niche?
The role or function of an organism within its community, including how it interacts with other organisms and its environment.
What shapes the niche of an organism?
The niche of an organism is shaped by its interaction with other organisms and abiotic factors in the ecosystem.
What is competition in ecology?
Organisms compete for resources like food, space, and mates.
What is predation?
The predator-prey relationship influences the population dynamics of species.
How does light affect organisms?
Some organisms may require specific light levels for photosynthesis or vision.
How does temperature affect organisms?
Organisms have different temperature requirements for survival.
How does nutrient availability affect organisms?
The amount of nutrients in the environment impacts an organism’s growth and reproduction.
What is unique about each organism’s niche?
Each organism’s niche is unique and helps maintain balance within the ecosystem.
What is interspecific competition?
Interspecific competition occurs when individuals of different species compete for the same resources in an ecosystem.
For example, in a forest, birds and squirrels might compete for the same type of seeds as food.
What is intraspecific competition?
Intraspecific competition occurs when individuals of the same species compete for resources.
For example, two male deer may compete for access to mates during the breeding season.
Types of stem cells
Tissue and Embryo
