CH:1 (Unit 1)

• Life processes—> MRSGREN

  M-movement

  R-respiration

  S-Sensitivity(Stimuli)

  G-Growth

  R-Reproduction

  E-Excretion

  N-Nutrition

  Also control their internal conditions
• Cell structure (types of cells)

  Prokaryote(no nucleus)—>unicellular(only one cell)

  Eukaryote (Contains nucleus)—>multicellular

  With and without cell wall

  without—>animalia

  with—>perform photosynthesis(plantae)

  does not perform—>fungi
• Differences between plant and animal cells (By elaborating structures in animal cells) —> animal contains only cell membrane, cytoplasm and nucleus, vacuole(temporary)

  
• cell wall


  -Protects and supports the cell, made out of cellulose
• freely permeable meaning

  -plant cells absorb water, has internal pressure against adjacent cells

  -is porous, not a barrier to water or dissolved substances
• cell membrane

  Controls entry and exit of the substances into the cell
• selectively/partially permeable meaning

  -forms a boundary between the cytoplasm of the cell and outside

  -not a complete barrier

  -can control the movement of some substances
• mitochondria

  where aerobic respiration takes place and releases energy in there
• nucleus

  controls the activities of the cell

  -contains chromosomes or genes
• ribosomes

  protein synthesis
• Vacuole

  Permanent feature, filled with cell sap, contains mineral ions and dissolved sugars
• Chloroplast

  Contains chlorophyll, carry out photosynthesis
• enzymes meaning


  biological catalysts, speeds up reaction without being used up itself
• types of enzymes


  intercellular (outside cells)

  extracellular (inside)
• why are enzymes needed?

  temperatures inside organisms are low

  without catalysts, reactions happen in cells would be far too slow to allow life to go on.

  speed them up
• Two other factors that affect enzymes

  Temperature and pH
• denature meaning

  change the shape of the active side so that the substrate will no longer fit into it
• What does Respiration do?

  Releases some heat energy, most is used to make ATP (Adenosine triphosphate)
• respiration equation


  glucose + oxygen —> carbon dixode +water

  C6H12O6+ 6O2. —> 6Co2 + 6H2O
• • what happens when energy is needed? (related to respiration)

  ATP can be broken down losing one phosphate group, forming ADP
• What happens during respiration?

  ATP is made from ADP and phosphate
• Aerobic respiration 


  respire without using oxygen

  two examples—> yeast cells and muscle cells
• In yeast cells, what is glucose broken down into?

  ethanol and carbon dioxide

  used for—> making bread and beer
• muscle cells(glucose broke down into?)

  glucose —> lactate + some energy
• during exercise, what rises?

  lactate
• oxygen debt definition

  the volume of oxygen that needed to completely oxidize the lactate that builds up the body during aerobic respiration.
• diffusion

  the net movement of particles from a region of high concentration to a region of low concentration, allows concentration gradient
• Active transport

  the movement of substances that is against concentration gradient and uses energy from respiration
• Osmosis 


  The net movement of water from a dilute solution to a more concentrated solution across the partially permeable cell membrane.