HS - LS1.C (B) - Synthesis of Macromolecules - FINAL (AuMy 1/30/2014)

DCI: LS1.C (B) The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules (such as proteins or DNA), used for example to form new cells.

DCI: LS1.C (C) As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

 PE: HS-LS1-6 Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.

PE: HS-LS1-7 Use a model to illustrate that cellular respiration is a chemical process whereby the bonds of food molecules and oxygen molecules are broken and the bonds in new compounds are formed resulting in a net transfer of energy.

[Clarification Statement: Emphasis is on using evidence from models and simulations to support explanations.] [Assessment Boundary: Assessment does not include the details of the specific chemical reactions or identification of macromolecules.]

[Clarification Statement: Emphasis is on the conceptual understanding of the inputs and outputs of the process of cellular respiration.] [Assessment Boundary: Assessment should not include identification of the steps or specific processes involved in cellular respiration.]

This standard comes immediately after another one that reads:

 The process of photosynthesis converts light energy to stored chemical energy by converting carbon dioxide plus water into sugars plus released oxygen.

So, we know the sugars referred to in this standard are those that are produced as a result of photosynthesis.  

The ideas in this standard are: 

- sugar molecules formed as a result of photosynthesis contain carbon, hydrogen, and oxygen

- the hydrocarbon backbones of sugar molecules are used to make amino acids and other carbon-based molecules

- these amino acids and other carbon based molecules can be assembled into larger molecules (proteins, DNA) which have uses including building new cells

- Matter and energy flow through different levels of living systems, as this happens, chemical elements are recombined in new ways to form different products (think photosynthesis, digestion, cellular respiration, etc.)

There will be several things to look at for this standard, which will hopefully make it somewhat easy to come up with 5 questions.  The first is simply the idea that sugar is composed of carbon, hydrogen, and oxygen.  After that, we can look more into the ideas that hydrocarbon backbones can be linked together to form amino acids, etc. The third concept is that chemical reactions take place inside living organisms, and that these reactions form new substances. 

In order to address the PEs, we can look into protein and amino acid synthesis, and get to the idea that the carbons necessary to build these chains came, originally, from sugars which entered the body through digestive processes (including cellular respiration).  We will have to provide evidence (diagrams, chemical formulas(?) that these long chains include carbon and have the students come up with the conclusion that these atoms of carbon, hydrogen, and oxygen are recombining to form new compounds. 

The second PE should be focused on to the inputs and outputs of cellular respiration (not comparing it to photosynthesis). The fact that it tells us to use a model of some sort means that we can use diagrams or conceptual models as well.  They should know the substances that go into the reaction, those that come out, and that there ends up being a net transfer of energy. Knowing the intricate steps of cellular respiration is not required. 

Possible Question Starters: 

"Sugar formed as a result of photosynthesis is made up of which of the following elements?"

-carbon, hydrogen, oxygen 

"The general structure for amino acids is shown.  (We would have to create a new image)

Amino groups are composed of an amino group, a hydrogen, a carboxyl group, and an "R" group, which is variable, depending on the particular amino acid.  The structure of amino acids, which are critical in building life-sustaining proteins, is evidence that - 

correct answer - carbon, which only enters the body when living things eat plants, is used to form other molecules

**Needs work**