TUGAS BIOLOGI_ uji fotosintesis

Posted in
22.00


UJI  FOTOSINTESIS

Tujuan : Membuktikan bahwa hasil fotosintesis berupa amilum / zat tepung.
A.    Bahan dan Alat
ü  Kaki tiga dan kasa                  1 buah
ü  Tabung reaksi                          1 buah
ü  Gelas kimia 500 cc                  1 buah
ü  Pinset                                      1 buah
ü  Cawanpetri                              1 buah
ü  Pipet tetes                               1 buah
ü  Korek api
ü  Kertas
ü  Penjepit tabung reaksi
ü  Alkohol
ü  Larutan yodium / lugol
ü  Daun berwarna dan tak berwarna hijau

B.     Cara Kerja
ü  Mencari daun yang berwarna dan tak berwarna hijau.
ü  Merebus daun dengan air mendidih agar sel – sel pada tumbuhan mati.
ü  Meniriskan daun pada kertas.
ü  Memasukkan daun yang telah direbus tadi dalam alkohol yang panas agar kandungan klorofil terlarut.
ü  Meniriskan daun setelah berwarna coklat pada cawan petri dan tetesi dengan lugol.

Tabel hasil pengamatan


Warna Daun Setelah

Keadaan Daun
Direbus dalam air mendidih
Direbus dalam alkohol
Ditetesi lugol
Daun yang terkena sinar matahari
Hijau kekuningan
Kuning
Kuning kecoklatan
Daun yang tidak terkena sinar matahari
Kuning
Putih bening
Putih kekuningan
Perbandingan :
Tepung kanji + larutan yodium / lugol berwarna biru kehitaman
Hasil diskusi
1.      Mengapa daun direbus dalam air mendidih? Jelaskan!
Jawab : Agar sel – sel daun mati.
2.  Apa tujuan daun direbus dalam alkohol panas, dan mengapa pemanasan alkohol tidak secara langsung?
Jawab : agar kandungan klorofil dalam daun terlarut, dan pembakaran tidak    dilakukan dengan secara langsung karena jika dilakukan secara langsung tabung reaksi akan meledak.
3. Bandingkan warna kedua daun hasil percobaanmu setelah ditetesi dengan lugol dan sebutkan warnanya!
Jawab : darah yang terkena sinar matahari berwarna kuning kecoklatan dan daun yang tidak terkena sinar matahari berwarna putih kekuningan.
4.  Bandingkan warna hasil percobaamu dengan warna zat tepung kanji yang ditetesi dengan larutan lugol / yodium! Kesimpulan apakah yang anda peroleh mengenai hasil fotosintesis?
Jawab : warnanya tidak sama, hasil percobaan daun yang terkena sinar matahari berwarna kuning kecoklatan, daun yang tidak terkena sinar matahari berwarna putih kekuningan, sedangkan yang tepung kanji berwarna biru kehitaman.
5.      Tuliskan reaksi kimia proses dari fotosintesis
      Jawab : (karbondioksia) + (air) di bantu dengan cahaya matahari = (glukosa)+(oksigen)
6.      Jelaskan arti dari fotosintesis! Sebutkan 4 syarat yang harus yang harus dipenuhi agar fotosintesis dapat berlangsung!
Jawab : fotosintesis adalah proses pembentukan karbohidrat dan bahan anorganik, berupa air dan karbondioksida dengan bantuan sinar matahari.
    Syarat fotosintesis = cahaya, kadar CO2, suhu, kandungan air dalam tanah.
7.      Mengapa tumbuhan hijau disebut organisme autotrof? Jelaskan!
Jawab : karena tumbuhan dapat mencari makanan dengan sendirinya dengan cara proses fotosintesis.
8.      Melalui apakah karbondipksida dari udara sampai ke tempat berlangsungnya proses fotosintesis?
Jawab : karbondioksida masuk kedalam daun melalui stomata.
9.      Pada tumbuhan tingkat tinggi, sebagian / logam manakah yang banyak terdapat kloroplas!
Jawab : daun.
10.  Mengapa pada siang hari bila kita duduk di bawah pohon yang rindang terasa sejuk? Jelaskan!
Jawab : karena tumbuhan sedang melakukan proses fotosintesis dan fotosintesis menghasilkan oksigen maka dari itu mengapa pada waktu siang hari apabila kita duduk di bawah pohon terasa sejuk.
  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • Twitter
  • RSS
Read Users' Comments (0)

kumpulan naskah story telling

Posted in
07.35


The Story Of The Lake Toba

Once upon a time, there was a man who was living in north Sumatra. He lived in a simple hut in a farming field. The did some gardening and fishing for his daily life.
One day, while the man was do fishing, he caught a big golden fish in his trap. It was the biggest catch which he ever had in his life. Surprisingly, this fish turned into a beautiful princess. He felt in love with her and proposed her to be his wife. She said; "Yes, but you have to promise not to tell anyone about the secret that I was once a fish, otherwise there will be a huge disaster". The man made the deal and they got married, lived happily and had a son.
Few years later, this son would help bringing lunch to her father out in the fields. One day, his son was so hungry and she ate his father’s lunch. Unfortunately, he found out and got furious, and shouted; “You damned son of a fish”. The son ran home and asked her mother. The mother started crying, felt sad that her husband had broke his promise.
Then she told her son to run up the hills because a huge disaster was about to come. When her son left, she prayed. Soon there was a big earthquake followed by non-stop pouring rain. The whole area got flooded and became Toba Lake. She turned into a fish again and the man became the island of Samosir.


The Ant and the Grasshopper

In a field one summer’s day a Grasshopper was hopping about, chirping and singing to its heart’s content. An Ant passed by, bearing along with great toil an ear of corn he was taking to the nest.
“Why not come and chat with me,” said the Grasshopper, “instead of toiling and moiling in that way?”
“I am helping to lay up food for the winter,” said the Ant, “and recommend you to do the same.”
“Why bother about winter?” said the Grasshopper; “We have got plenty of food at present.” But the Ant went on its way and continued its toil.
When the winter came the Grasshopper had no food and found itself dying of hunger – while it saw the ants distributing every day corn and grain from the stores they had collected in the summer. Then the Grasshopper knew: It is best to prepare for days of need.
 

The Monkey's Trick


mr. monkey realized that mr. crocodile was very bad. mr.crocodile loved to bully all the small and the weak animals.

therefore, mr monkey hated mr crocodile. mr crocodile had even tried to attack and swallow mr monkey

"he's strong and big. and he thinks that he's the smartest", said mr monkey to himself."what can i do to teach him a lesson?", thought mr monkey.

one day, mr monkey saw mr crocodile holding a frightened bird in his hands. mr monkey became very worried

however, the bird managed to escape from mr crocodile's hand. mr crocodile was very upset but mr monkey jumped happily.

" i must find ways to teach him a lesson," said me monkey. but mr monkey wasn't sure what to do.

after a few days, mr monkey came up with an idea. he went arround the woods to look for fine vines. "these vines are going to be veru useful to me," said mr monkey. he then tied a stone to the vine. he was very eager to teach mr crocodile a lesson.

and mr monkey proceeded to the river. nobody knew about his plan.

"ah, me monkey is here! i should catch and eat him today," said mr crocodile. mr monkey was sitting on a branch, by the river, with his tail touching the river.

"this is a right time for me to catch him," said mr crocodile. he swam quietly towards mr monkey. "i'm going to have a hearty meal today," thought mr crocodile

mr crocodile swam nearer and nearer to mr monkey. mr monkey pretended not to see mr crocodile." this time i'll teach him a lesson," said mr monkey

  • Digg
  • Del.icio.us
  • StumbleUpon
  • Reddit
  • Twitter
  • RSS
Read Users' Comments (0)
Langganan: Komentar (Atom)