5 Flashcards
Synapse
A synapse is a connection between neurons and other neurons, glands, muscles, and receptors. A synapse consists of a presynaptic and postsynaptic neuron, which have a gap between them called the synaptic cleft, allowing for the movement of nerve signals from one neuron to another.
What increases the speed of conduction along a neuron?
A neuron increases its speed of conduction when its axon diameter and myelination also increase. Myelination acts as an insulator and forces the impulse to “jump” along the axon from node to node.
Acetylcholine
Acetylcholine is a neurotransmitter that consists of choline and an acetyl group. When acetylcholine is released by exocytosis, it binds to the receptors on the postsynaptic neuron, initiating depolarization. If a threshold is reached, an action potential will occur. Once the neurotransmitter is released, it will be broken down into choline and acetate.
Cellular respiration
Cellular respiration is the gradual and controlled release of energy by breaking down organic compounds to produce ATP. Cellular respiration begins with Glycolysis, which splits glucose to make pyruvate. Then, the Krebs Cycle uses pyruvate to make NADH. Then, the Electron Transport Chain uses NADH to transport electrons and H+. Then, H+ passes through ATP synthase to make ATP.
Photosynthesis
Photosynthesis is the reaction of CO2 and water using energy from light. Photosynthesis takes place in chloroplasts. Photosynthesis produces carbohydrates and releases oxygen as a waste product.
Limiting factor
A limiting factor is a factor that restricts the rate of a reaction. 3 limiting factors that can limit the rate of photosynthesis are light, CO2, and temperature.
Photolysis
Photolys uses light energy to break apart a water molecule to generate electrons. Photolysis takes 2 water molecules and photons and converts it into 4 electrons, 4 hydrogen molecules, and oxygen.
Photoactivation
Photoactivation uses energy from light to excite electrons in chlorophyll pigment. This occurs so that electrons can leave the pigment molecule and move through the electron transport chain. Photoactivation occurs in Photosystem II and I.
What kind of reaction is photosynthesis?
Photosynthesis is an example of an anabolic reaction. This is because small molecules, CO2 and water, are joined together to form large molecules, sugars.
Light-dependent versus light-independent reactions
Light-dependent reactions occur in the thylakoids and are where light energy is converted to ATP and NADPH. Light-dependent reactions produce oxygen gas as a waste product. Light-independent reactions (or the Calvin cycle) occur in the stroma and are where carbohydrate molecules are synthesized using energy from ATP and NADPH.
Catabolism versus anabolism
Catabolism is the breakdown of complex molecules into simpler molecules. Anabolism is the synthesis of complex molecules from simpler molecules.
Use of water as a coolant in sweat
Sweat is a liquid made up of mostly water. An organism sweats when the sweat becomes warm enough to evaporate from the body’s surface. Sweating removes excess heat and thus cools the body.
Cellulose, starch, and glycogen
Cellulose and starch are found in plants. Cellulose provides strength to the plant cell wall. Starch stores energy and acts as a source of carbon for photosynthesis. Glycogen is found in humans. Glycogen is broken down to release glucose when the body needs an energy boost.
Unsaturated versus saturated fatty acids
Unsaturated fatty acids are made up of double bonds. Unsaturated fatty acids remain solid at room temperature and can lead to fatty deposits in blood vessels. Saturated fatty acids are made up of single bonds. Saturated fatty acids remain liquid at room temperature and are less likely to clog arteries.
Sodium potassium pumps
Sodium and potassium move against their concentration gradients. Sodium potassium pumps help maintain osmotic equilibrium by maintaining a high concentration of sodium extracellularly and a high level of potassium intracellularly.
