뒤로General Biology: Key Concepts and Core Practicals
04:26
이 집합의 용어 (30)
Eukaryotic cells have a nucleus and membrane-bound organelles; prokaryotic cells lack a nucleus and have circular DNA and plasmids.
Contains DNA coding for proteins needed to build new cells, enclosed in a nuclear membrane.
Site of aerobic respiration reactions, providing energy for the cell.
Where protein synthesis occurs, found on rough endoplasmic reticulum.
Chloroplasts for photosynthesis, permanent vacuole for rigidity, and cell wall made of cellulose.
Cell wall made of peptidoglycan, cell membrane, cytoplasm, circular chromosomal DNA, plasmids, and sometimes flagella.
Process where cells gain new sub-cellular structures to become specialised for a specific function.
Streamlined head, long tail for swimming, many mitochondria for energy, acrosome with enzymes, and haploid nucleus.
Specialised for water uptake by osmosis and mineral ions by active transport, with large surface area and mitochondria.
Transport water and minerals from roots to shoots; lignin deposits cause cells to die and form hollow tubes.
Carry products of photosynthesis through sieve plates; companion cells provide energy via mitochondria.
Up to 2000x magnification and 200nm resolving power, used to view cells and large organelles.
Use electrons for higher resolution (down to 0.2nm), magnification up to 2,000,000x, can view viruses and small organelles.
\(\text{Magnification} = \frac{\text{size of image}}{\text{size of object}}\)
Substrate fits exactly into enzyme's active site forming enzyme-substrate complex, enabling the reaction.
Activity increases to an optimum (~37°C in humans), then decreases rapidly as enzymes denature above this.
Enzymes have an optimum pH; too high or low pH changes active site shape, causing denaturation and loss of function.
Rate increases with substrate concentration until saturation point, where all active sites are occupied.
Iodine turns blue-black in presence of starch, indicating starch breakdown by amylase over time.
\(\text{Rate} = \frac{\text{Change}}{\text{Time}}\)
Carbohydrases break carbs into sugars, proteases break proteins into amino acids, lipases break lipids into fatty acids and glycerol.
Add iodine solution; blue-black color indicates presence of starch.
Add Benedict's solution and heat; reddish-brown precipitate indicates reducing sugars.
Biuret test: add potassium hydroxide and copper sulfate; violet color indicates protein.
Emulsion test: add ethanol and water; white emulsion layer indicates lipids.
\(\text{Energy} = \text{mass of water} \times 4.2 \times \text{temperature increase}\)
Passive movement of molecules from high to low concentration without energy.
Passive movement of water from dilute to concentrated solution across a selectively permeable membrane.
Energy-requiring movement of molecules against concentration gradient using ATP.
Measure percentage gain or loss of mass in potato disks placed in sucrose solutions of different concentrations.