Biology- Topic 1/ Key concepts Flashcards
Eukaryotic cells have:
Membrane bound organelles such as a nucleus, mitochondria and ribisomes.
Prokaryotic cells have:
No membrane bound organelles.
Bacteria- DNA
One large loop of chromosomal DNA and smaller loops of plasmids
Bacteria specialised
Additional capsule/slime layer and the flagellum tail to propel itself
Nucleus
Controls activities of the cell and DNA
Cytoplasm
Jelly like substance where chemical/ metabolic reactions take place
Ribisomes
Protein synthesis
Mitichondria
Where aerobic reactions take place (respiration and ATP)
Cell membrane
Controls what enters and exits the cell, partially permeable
Chloroplasts
Green dye that absorbs sunlight for photosynthesis
Cell Wall- Plants
Made of cellulose is fully permeable and gives the plant structure
Large Permanent Vacuole
Storage of sap and gives the plant structure
How are sperm cells adapted to their functions?
Acrosome/ streamline shape- holds digestive enzymes.
Midpiece- Holds many Mitochondria for energy.
Flagellum- Swim to the egg.
Haploid nucleus- single set of chromosomes that contains to right information for the fetus growth.
How are egg cells adapted to their functions?
Haploid nucleus- single set of chromosomes that contains to right information for the fetus growth.
Nutrients in cytoplasm- for the early growth of the fetus.
changes in cell membrane- only one sperm can enter
How are ciliated cells adapted to their functions?
Many mitochondria to make cilia hairs move and woft micros and debris out of airways.
Electron microscopes vs light microscopes
electron microscopes due to the shorter wavelength of electrons than light, produce images with higher resolution.
Magnification calculation
Image= Magnification x actual size
What do enzymes do?
Enzymes bind to substrates from their active site and speed up metabolism.
How can enzymes be denatured?
Temperature- too much kinetic energy breaks enzymes intermolecular bonds.
pH- Presence of more h+ ions or OH- ions can change the active site
Substrate concentration- With more substrate than enzymes peak rate will be attained meaning the graph will be still.
Rate
rate =
change/time
How to test for starch?
Place iodine into wells on a dimple tile with food samples. Iodine will go from yellow- blue
How to test for Protein?
Add buirite into wells on a dimple tile with food samples. It will go blue to purple
How to test for sugar?
Place benedicks in a test tube with food samples and place in hot water bath for 5 minutes. Yellow-orange-red
How does calorimetry measure energy in food?
By burning food in the combustion chamber use a thermometer to calculate the difference in temperature. Use the equation energy= ((final temp-start temp) x 4.2 x volume of water)/ mass of food
How to calculate percentage change in osmosis
(Final mass- initial mass)/ initial mass
multiply by 100.
