Monthly Archives: September 2013

The Heirarchy of Life

For homework, please watch the following video from Mr Anderson’s Bozeman Biology channel on Youtube and complete the Google form I sent you. I’ve also embedded the form below the video, but you can only see it when you are logged into your IST gmail account.

Link

Curiosity Water Discovery on Mars

Image credit: NASA/JPL-CalTech

Image credit: NASA/JPL-CalTech

Mars has always fascinated humans, and continues to do so. Here’s a little tidbit about our red neighbor, courtesy of NASA and the BBC:  http://www.bbc.co.uk/news/science-environment-24287207

Planning the Photosynthesis and Respiration Lab

I’ll add more later, but for the moment, please use this lab report planner to develop the investigation you will design into photosynthesis and respiration in Philodendron hastatum and Sansevieria trifasciata.

Below is a link to the planner as a Google form. When you complete the planner and click ‘submit,’ I will receive a digital version of your responses, which means I can then quickly see what you’re planning for your investigation and give you some timely feedback in class. ***Please note that you must be signed in to your IST Gmail account in order to see and use the planner form!

Click on the following link to download a MS Word version of the planner. It covers all parts of the lab report process in MYP science and is a little more detailed than the embedded Google form above. Photosynthesis-Respiration Lab Report Planner

Photosynthesis Experiment #7

Sansevieria trifasciata

Sansevieria trifasciata

This week in grade 9 science, we’ll start the process of developing your investigations into photosynthesis and respiration in Sansevieria trifasciata and Philodendron hastatum plants. The first steps of that process are a couple of preliminary experiment to establish an understanding of these essential processes.

Philodendron hastatum

Philodendron hastatum

The experiment below is the one we’ll be doing in class on Thursday and Friday of this week. Please make sure you’ve read all the way through the procedure before we start in the lab!

You will submit digital versions of the data tables and the analysis questions for homework after you’ve finished this experiment. You may send them via email.

Video

Biological Molecules

Well, today was a little wacky, with no electricity or projector, class photographs in the middle of one class, and virtually no air circulating in my room to make for a hot hot hot day at school. Add in the noise and distraction of holding class in the courtyard, and we have….well, we have a bit of a mess.

Just so we’re all on the same page of the biology unit, I thought I’d summarize the key points from today’s lesson on biological molecules. Below are the finer points of the lesson.

The 3 major functions of all biological molecules

  1. Instructions
  2. Energy storage
  3. Source of energy

Screen Shot 2013-09-24 at 3.02.57 PMCarbohydrates

  • chains of C, H, and O
  • supply all energy in cells and food chains
  • energy tends to be short-term energy (glycogen)
  • simple sugars such as glucose may build more complex molecules
  • some long chains of sugars, such as cellulose, are used for cellular structure

Screen Shot 2013-09-24 at 3.03.49 PMLipids

  • do not dissolve in water
  • long chains of C, H, O, and P
  • have more bonds than carbs, so they’re used for energy storage
  • slow release of energy
  • saturated fats: all single C-H bonds, tend to be solids
  • unsaturated fats: some C-C double bonds, tend to be liquids (oils)
  • Image credit: http://www.uic.edu

    Image credit: http://www.uic.edu

    phospholipids make up cell membranes and have two main parts:

    • a phosphate group at one end, which is polar (charged), meaning it is hydrophilic
    • the hydrophobic hydrocarbon tails

Proteins

  • most important biological molecule
  • many functions in organisms:
    • enzymes
    • structural components (building blocks)
    • hormones
    • antibodies
  • made of chains of amino acids
  • only 20 amino acids make all the 1000’s of proteins in the world

Nucleotides

  • made of C, H, O, P, and N
  • 3 parts of each nucleotide:
    • nitrogen base
    • sugar
    • phosphate
  • Screen Shot 2013-09-24 at 3.03.33 PM

    4 different nitrogen bases to know: A-C-G-T (shown at right)

  • several functions in organisms:
    • chemical messengers
    • coenzymes
    • carry energy from one part of a cell to another
    • build nucleic acids
  • two kinds of nucleic acids:Screen Shot 2013-09-24 at 3.03.20 PM
    • DNA: sequence of nucleotides makes up the genetic code of an organism
    • RNA: translates the code into specific proteins

And finally, the slides from class…

 

Video

Plants and Animals: Cellular Differences

Plants and animals are both eukaryotes, meaning they have distinct nuclei. (Bacteria, by contrast, are prokaryotes, which means they don’t have a nicely organized nucleus.)

Plants and animal cells have many other similarities: ribosomes, mitochondria, chromatin, cell membranes, smooth and rough endoplasmic reticula (ER), vacuoles, and Golgi complexes, among some other organelles we’re not studying in this unit. However, there are some fundamental differences between plants and animals on a cellular level:

  • cell wall in plants
  • chloroplasts (plastids) in plant cells
  • large central vacuole in plant cells
  • centrioles in animal cells
  • some differences in the structure and function of the Golgi complexes

Watch this video for a nice summary, and please do click on the links he posts at the end for a deeper explanation of the topics he covers.

The following video is a bit more ‘scientific’ and uses some nice computer animation to tour plant cells. It’s worth a quick watch, too.

Ig Nobel Prizes Awarded!

Check out some of these wacky – but real! – investigations by genuine, getting-paid-to-do-it scientists! If you’ve got an oddball interest, there just may be research funding in your future….

Ig Nobel Awards Salute Science’s Wacky Side