Photosynthesis

• biology, physics and chemistry
• photosynthesis is the process by which plants convert light energy into chemical energy
• chlorophyll absorbs most strongly at wavelengths around 430nm (blue) and 650nm (red)
• the chloroplast has two membranes that enclose an internal fluid called stroma
• light-dependent reactions occur within the thylakoids
• the chloroplast contains thylakoid membranes that contain photosystems
• the chloroplasts are found within the mesophyll cells of leaves
• mesophyll cells have large surface areas to maximise gas exchange with air
• stomata are small openings on the underside of the leaf that allow carbon dioxide to enter and oxygen to leave
• carbon fixation occurs when CO2 enters the plant through stomata and combines with H2O to form glucose
• chlorophyll absorbs most strongly at wavelengths around 430nm (blue) and 662nm (red)
• water evaporates out of the leaf through the same stomata
• photosynthetic pigments absorb light energy from sunlight, which is then used to convert water into glucose

  
• carbon dioxide diffuses across the cell wall and plasma membrane of guard cells surrounding the stomata
• carbon dioxide enters through stomata on the undersides of leaves
• photosynthetic pigments absorb light energy from sunlight, which is then used to convert carbon dioxide into glucose
• stroma is the fluid inside the chloroplast
• during the light independent reaction, carbon dioxide from the air enters the plant through stomata on the undersides of the leaves
• grana are clusters of thylakoid membranes
• in the light dependent reaction, water molecules are split to release oxygen gas and hydrogen ions
• photosynthetic pigments absorb light energy from sunlight, which is used to drive chemical reactions
• light energy absorbed by pigments is used to split water molecules into hydrogen and oxygen atoms
• accessory pigments such as carotenoids and phycobilins absorb other wavelengths of visible light
• photosystem II is located nearer the top of the thylakoid stack, while photosystem I is located lower down
• photosystem II is located in the thylakoid membrane, where it uses light energy to split water molecules into hydrogen and oxygen
• hydrogen atoms combine with NADP+ to produce NADPH which carries electrons from light reactions to Calvin cycle
• light-dependent reactions occur in the stroma of the chloroplast
• in photosynthesis, electrons from water are used to reduce NADP+ to NADPH
• the chloroplast contains thylakoids where photosystems are located
• Table of Contents


  • HOW TO ANSWER MULTIPLE CHOICE QUESTIONS LIKE A PRO
  • LANGUAGE PROFICIENCY
  • SCIENCE
  • MATHEMATICS
  • READING COMPREHENSION
  • LANGUAGE ANSWER KEY
  • SCIENCE ANSWER KEY
  • MATHEMATICS ANSWER KEY
  • READING ANSWER KEY
• How to Answer Multiple Choice Questions Like A Pro

  1. Between a multiple choice test and an essay exam, most of us would rather choose the former

  2. Multiple choice tests trick our brains that they're easier to answer

  3. All we have to do is to distinguish the correct answer from the distracters

  4. Answering multiple choice exams are not as easy or straightforward as we like them to be, especially if we're dealing with crucial exams like the UPCAT
• Tips for answering multiple-choice exams

  • They are a perfect supplement to your hard-earned stocked knowledge and can maximize your success in answering any multiple-choice exam
• Be wary of tricks and traps
• The goal of test makers is to gauge your analytical skills in all subtests
• Tricks and traps


  • They may be easy to identify but the more subtle ones are what you should watch out for
  • Don't overanalyze but never trust questions that are too easy either
• Language proficiency exams


  The following traps may lead you to the path of failure if you're not careful
• Violation of the rule of "parallel structures"

  Parallel structures are used to ensure clarity of statements. Words and phrases in a sentence should be consistent in terms of structure and tense
• Violation of the rule of "parallel structures"


  • Example: "Play, eat, and sleeping--these are what my pet dog usually does all day."
• Insertion of distracting phrase or clause that clouds subject-verb agreement

  Always focus on two things: the subject and the verb. In the above example, the subject is "politicians" which is in plural form so the verb must also be plural
• Insertion of distracting phrase or clause that clouds subject-verb agreement


  • Example: "Many politicians, in their desire to win an election, makes grandiose promises to voters."