Berkas Mapel SMA X-XII

berisi materi2 pelajar SMA

Global Warming, Issue or Fact?


 

Abstract

 

Global warming is the term used to describe a gradual increase in the average temperature of the Earth’s atmosphere and its oceans, a change that is believed to be permanently changing the Earth’s climate. There is great debate among many people, and sometimes in the news, on whether global warming is real (some call it a hoax). But climate scientists looking at the data and facts agree the planet is warming. While many view the effects of global warming to be more substantial and more rapidly occurring than others do, the scientific consensus on climatic changes related to global warming is that the average temperature of the Earth has risen between 0.4 and 0.8 °C over the past 100 years. The increased volumes of carbon dioxide and other greenhouse gases released by the burning of fossil fuels, land clearing, agriculture, and other human activities, are believed to be the primary sources of the global warming that has occurred over the past 50 years. Scientists from the Intergovernmental Panel on Climate carrying out global warming research have recently predicted that average global temperatures could increase between 1.4 and 5.8 °C by the year 2100. Changes resulting from global warming may include rising sea levels due to the melting of the polar ice caps, as well as an increase in occurrence and severity of storms and other severe weather events. (lebih…)

Pertanyaan & Diskusi “Kerja Enzim Katalase”


 

sumber gambar: Alit Adi Sanjaya (blogspot)

  1. Pada perlakuan manakah pembentukan gelembung paling banyak? Mengapa demikian?
    Pada ekstak hati dan H2O2, karena di dalam hati mengandung enzim katalase yang berguna untuk menetralkan racun dimana hanya dapat bekerja optimal pada ph netral. Sedangkan pada campuran hati dengan KOH dan HCl tidak akn menghasilkan gelembung yang terlalu banyak, karena pH larutan menjadi basa dan asam.
  2. Gas apakah yang terbentuk pada reaksi tersebut?
    Gas O2, karena ekstrak hati yang ditambah H2O2, akan menimbulkan gelembung gas O2. Apabila bara api ditempatkan ke dalam tabung reaksi tersebut, bara api akan menyala dan membuktikan bahwa reaksi pembakaran tadi menghasilkan O (lebih…)