Life processes Flashcards
Active transport
The movement of substances against a concentration gradient using energy from respiration
Osmosis
Net movement of water from a dilute solution to a more concentrated solution across a partially permeable cell membrane
Diffusion
Net movement of particles from a region of high concentration to a region of low concentration (i.e. down a concentration gradient)
Enzymes
Are biological catalysts in a reaction that speeds it up
Lock and key model
The enzyme will only catalyse one reaction, substrate enters enzyme’s active site, products are formed which leave active site
Effect of pH on enzymes
Optimum is often pH 7. On either side of this neutral, the shape of the active site will change/structure of enzyme is affected.
Investigating pH
Potato extract, buffer (pH7), and catalase solution in test tube and count number of bubbles in a beaker of water
Effect of temperature on enzymes
High temperature give enzyme and substrate molecules more kinetic energy so they collide more often, leading to reaction taking place more frequently. Optimum is often 40C. Too high, and the enzyme will denature, taking a permanent shape.
Investigating temp
Amylase and starch solution with different temperature water bath, place with Pipette on tray with iodine solution every 30 secs for 10 mins
Animal cell organelles
Nucleus
Cell membrane
Mitochondria
Cytoplasm
Plant cell organelles
Nucleus
Cell membrane
Mitochondria
Cytoplasm
Vacuole
Chloroplasts
Cell wall
Mitochondria
Respiration occurs here so muscles and nerve cells have lots of them
Aerobic respiration
Use of oxygen and glucose to release carbon dioxide and water (and energy, most used to make ATP)
Anaerobic respiration
Without oxygen, glucose is not completely broken down, less energy is released
Yeast cell respiration formula
Glucose -> ethanol + CO2 (+ some energy)
