Unit 1 Study Guide

Which set of elements is most abundant in living organisms?

• Sodium, Calcium, Phosphorus, Chlorine

• Carbon, Hydrogen, Nitrogen, Oxygen

• Oxygen, Sulfur, Phosphorus, Magnesium

• Potassium, Hydrogen, Nitrogen, Carbon

What happens when magnesium (Mg) with two valence electrons bonds with oxygen (O) with six valence electrons?

• They share electrons equally, forming a nonpolar covalent bond

• Magnesium gives away two electrons, forming Mg²⁺ and O²⁻ ions that attract

• Oxygen donates two electrons to magnesium, making a metallic bond

• Electrons are pooled in a 'sea,' forming delocalized metallic bonds

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Why can water travel from roots to leaves in tall plants?

• Cohesion and adhesion maintain a continuous water column

• Ionic bonding between water and xylem walls pushes water upward

• Water is pumped upward by root pressure alone

• Capillary action caused by nonpolar bonds

How does the bicarbonate buffer system respond if blood becomes too basic (pH rises)?

• Carbonic acid releases H⁺

• Bicarbonate binds extra H⁺

• Water molecules form OH⁻

• The pH does not change at all

Tags

NGSS.HS-LS1-3

What functional groups are present in every amino acid?

• Hydroxyl and methyl

• Amino and carboxyl

• Phosphate and amino

Why can amino acids act as both acids and bases?

• They contain only nonpolar side chains

• The amino group can accept H+ and the carboxyl group can donate H+

• They always form buffers with water

• They have sulfur groups that bind protons

If Solution X is pH 3 and Solution Y is pH 6, how much more acidic is X than Y?

• 3 times

• 30 times

• 1000 times

• 10 times

When a strong base is added to a weakly acidic solution, what typically happens?

• pH instantly drops

• pH instantly rises to 14

• pH increases gradually and stabilizes if a buffer is present

• pH does not change at all

When CO₂ dissolves in blood, what happens to pH?

• It increases slightly

• It decreases slightly

• It stays the same

• It first increases, then decreases sharply

Which is a mismatched monomer/polymer pair?

• Monosaccharide / Polysaccharide

• Amino acid / Protein

• Triglyceride / Phospholipid bilayer

• Nucleotide / DNA