Question

2.2 student activity sheet lesson 2 search for life
lesson 2: why are these substances so important for life?
unit question: how should we search for life beyond earth?
lesson 2: student activity sheet

1. complete the table below for the molecules/ions stations.

table with rows: molecule (phospholipids, membrane proteins, nucleic acids, carbohydrates); columns: elements involved, water’s role, where are the charges? (+) and (-), what patterns do you observe in how the elements connect?
name: steffani
period: 2
date: ______

Explanation:

To complete the table, we analyze each molecule:

1. Phospholipids

• Elements Involved: C, H, O, N, P (carbon, hydrogen, oxygen, nitrogen, phosphorus).
• Water’s Role: Hydrophilic head (attracts water) and hydrophobic tail (repels water) → forms cell membranes (bilayer).
• Where are the charges? (+) and (-): Head (phosphate group) is \(\boldsymbol{-}\) (negative); tail (fatty acids) is neutral.
• Patterns in Elements: Contains P (unique to phospholipids among these), plus C, H, O, N.

2. Membrane Proteins

• Elements Involved: C, H, O, N, (S) (carbon, hydrogen, oxygen, nitrogen, sometimes sulfur).
• Water’s Role: Integral proteins (span membrane, interact with water on both sides); peripheral proteins (attach to membrane surface, interact with water).
• Where are the charges? (+) and (-): Amino acid side chains (e.g., acidic: \(-\); basic: \(+\)) → overall charge varies.
• Patterns in Elements: Primarily C, H, O, N (like nucleic acids/carbohydrates, but with N - based structure).

3. Nucleic Acids (DNA/RNA)

• Elements Involved: C, H, O, N, P (carbon, hydrogen, oxygen, nitrogen, phosphorus).
• Water’s Role: Dissolve in water (aqueous environment); water stabilizes structure (e.g., H - bonds in DNA).
• Where are the charges? (+) and (-): Phosphate group (\(-\)); nitrogenous bases (neutral); sugar (neutral) → overall \(-\) from phosphate.
• Patterns in Elements: Contains P (like phospholipids), plus C, H, O, N.

4. Carbohydrates (e.g., Glucose)

• Elements Involved: C, H, O (carbon, hydrogen, oxygen; ratio ~ \(C_n(H_2O)_n\)).
• Water’s Role: Soluble in water (hydrophilic); water breaks down (hydrolysis) or builds (dehydration) carbs.
• Where are the charges? (+) and (-): Neutral (no charged groups in simple carbs; some complex carbs have \(-\) from functional groups).
• Patterns in Elements: Only C, H, O (no N/P/S) → distinct from others.

Filled Table (Summary):

Molecule	Elements Involved	Water’s Role	Where are the charges? (+) and (-)	Patterns in Elements
Membrane Proteins	C, H, O, N (S)	Integral/peripheral (interact with water)	Side chains: \(+\)/\(-\); overall variable	Primarily C, H, O, N; N - based structure
Nucleic Acids	C, H, O, N, P	Dissolve/stabilize (H - bonds)	Phosphate: \(-\); bases/sugar: neutral	Contains P; C, H, O, N
Carbohydrates	C, H, O	Soluble/hydrolysis/dehydration	Neutral (or \(-\) in complex carbs)	Only C, H, O (no N/P/S)

This table organizes key biochemical properties for each molecule, aligning with concepts in Biology (subfield of Natural Science).

Answer:

To complete the table, we analyze each molecule:

1. Phospholipids

• Elements Involved: C, H, O, N, P (carbon, hydrogen, oxygen, nitrogen, phosphorus).
• Water’s Role: Hydrophilic head (attracts water) and hydrophobic tail (repels water) → forms cell membranes (bilayer).
• Where are the charges? (+) and (-): Head (phosphate group) is \(\boldsymbol{-}\) (negative); tail (fatty acids) is neutral.
• Patterns in Elements: Contains P (unique to phospholipids among these), plus C, H, O, N.

2. Membrane Proteins

• Elements Involved: C, H, O, N, (S) (carbon, hydrogen, oxygen, nitrogen, sometimes sulfur).
• Water’s Role: Integral proteins (span membrane, interact with water on both sides); peripheral proteins (attach to membrane surface, interact with water).
• Where are the charges? (+) and (-): Amino acid side chains (e.g., acidic: \(-\); basic: \(+\)) → overall charge varies.
• Patterns in Elements: Primarily C, H, O, N (like nucleic acids/carbohydrates, but with N - based structure).

3. Nucleic Acids (DNA/RNA)

• Elements Involved: C, H, O, N, P (carbon, hydrogen, oxygen, nitrogen, phosphorus).
• Water’s Role: Dissolve in water (aqueous environment); water stabilizes structure (e.g., H - bonds in DNA).
• Where are the charges? (+) and (-): Phosphate group (\(-\)); nitrogenous bases (neutral); sugar (neutral) → overall \(-\) from phosphate.
• Patterns in Elements: Contains P (like phospholipids), plus C, H, O, N.

4. Carbohydrates (e.g., Glucose)

• Elements Involved: C, H, O (carbon, hydrogen, oxygen; ratio ~ \(C_n(H_2O)_n\)).
• Water’s Role: Soluble in water (hydrophilic); water breaks down (hydrolysis) or builds (dehydration) carbs.
• Where are the charges? (+) and (-): Neutral (no charged groups in simple carbs; some complex carbs have \(-\) from functional groups).
• Patterns in Elements: Only C, H, O (no N/P/S) → distinct from others.

Filled Table (Summary):

Molecule	Elements Involved	Water’s Role	Where are the charges? (+) and (-)	Patterns in Elements
Membrane Proteins	C, H, O, N (S)	Integral/peripheral (interact with water)	Side chains: \(+\)/\(-\); overall variable	Primarily C, H, O, N; N - based structure
Nucleic Acids	C, H, O, N, P	Dissolve/stabilize (H - bonds)	Phosphate: \(-\); bases/sugar: neutral	Contains P; C, H, O, N
Carbohydrates	C, H, O	Soluble/hydrolysis/dehydration	Neutral (or \(-\) in complex carbs)	Only C, H, O (no N/P/S)

This table organizes key biochemical properties for each molecule, aligning with concepts in Biology (subfield of Natural Science).