The amino acid histidine has ionizable groups with pK, values of 1.8, 6.0, and 9.2, as shown. coo H₂N-CH COOH H₂N-CH CH, H pH = lonizable -COOH group CH 1.29 Incorrect COO H₂N-CH 1.8. pk, CH, H CH COO™ 6.0 pk₂ CH, H C H N -HisH -His CH COO —NH ---NH, A biochemist makes up 85 mL of a 0.10 M solution of histidine at a pH of 5.5. She then adds 60 mL of 0.10 M HCI. What is the pH of the resulting solution? H₂N-CH CH, H 9.2 C pk, H N CH Macmillan Leamin T in dis be the (His IM.

Match the following amino acids with their chemical properties H -N-CIC- A -A ✓ B но с D VE ✓ F ✓ G / CH3 CH3 CH B H но -N-C-C- feed C но -N-C-C- H CH₂ D HO -N-CIC- 1 H CH₂ OH E но ||| -N-C-C- II H CH₂ I CH₂ CH₂ CH₂ T NH3 I. Acidic II. Nonpolar III. Polar uncharged IV, Basic + F O HO -N-C-C- H CH₂ NH₂ G но | || -N-C-C- I H CH₂ 1

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The amino acid histidine has ionizable groups with pKą values of 1.8, 6.0, and 9.2, as shown. COOH T H₂N-CH | CH₂ H -O pH UT = ZI Ionizable -COOH group CH H₂N-CH T 1.8 COO- pk₁ CH2 UI COO™ H IZ CH -HisH+ COO™ + H₂N-CH 6.0 pK₂ CH ₂ UI -His H CH -NH COO™ H₂N-CH 9.2 pk3 CH ₂ UI —NH₂ H A biochemist makes up 80 mL of a 0.11 M solution of histidine at a pH of 5.1. She then adds 60 mL of 0.10 M HCl. What is the pH of the resulting solution? CH

nts 49 arning irtual Incorrect Question 73 How is the following amino acid classified? 0 H3N-CHC-0 CH2 C=O udent 3 polar neutral None of the above is a correct classification. nonpolar polar acidic polar basic 0/2 pts

Now let us look at a real amino acid, alanine. Fill in the chart below for each ionizable group. You need only the relationship discussed in the pdf posted and the numbers posted below. The next 6 questions will ask for the numbers you calculated for each of the letters below. pH when Average charge of group Group Ka pKa [A]/[HA] = 1 when pH = pK alpha-COOH ~10-2 A C alpha-NH3* ~10-9 В

How is this wrong?

Q2

ball & stick This amino acid is Not started Submit Answer - + labels to access important values if needed for this question. Retry Entire Group 9 more group attempts remaining < ENG 6

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