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CHEM 153A

Biochemistry: Introduction to Structure, Enzymes, and Metabolism

4 units

Sections & times

Lecture and discussion. The registrar has published a final exam time.

Fall 2026: 2 lectures and 24 discussions. 2 lectures and 10 discussions are open. The oldest of these readings was 3 hours ago.

Grades

3.31

Average grade awarded in CHEM 153A. Not a student rating: this is what the grades were.

In the A range

55%

of the 7,554 letter grades

D, F or W

4.8%

of every letter grade awarded, plus withdrawals

Taken pass/no pass

<1%

55% of those passed

The registrar's own records: 7,554 grades over 14 terms, Fall 2021 to Fall 2025. Every instructor is pooled here.

What is inside that record

2 of those terms are summer sessions, and summer sessions are counted here.

The table below splits them, and term averages across those 14 terms ran 3.12 to 3.41.

Historical grades for LANNAN, RYAN, across recorded terms. The course summary above includes all professors.

  • A+ 1,137 · 20.2%
  • A 1,271 · 22.6%
  • A- 770 · 13.7%
  • B+ 596 · 10.6%
  • B 599 · 10.6%
  • B- 351 · 6.2%
  • C+ 249 · 4.4%
  • C 244 · 4.3%
  • C- 105 · 1.9%
  • D+ 75 · 1.3%
  • D 69 · 1.2%
  • D- 45 · 0.8%
  • F 122 · 2.2%
  • P 10 of 5,681
  • NP 10 of 5,681
  • I 28 of 5,681

Percentages are of the 5,633 letter grades. Grey bars are non-letter outcomes: passes (P), no-passes (NP), and incompletes (I).

How the non-letter outcomes are counted

They are excluded from the GPA entirely rather than scored, because counting a P as a 4.0 would be a fabrication.

By instructor

Predicted GPA, raw average, sample size, terms, A range and the workload reviewers reported for every instructor with a grade record in this course
Instructor Predicted GPA Raw n Terms A range Workload Fall 2026
LANNAN, RYAN reviews ↗ 3.31 3.31 5,633 11 56% light Open, 5 seats left
ELLIS GUARDIOLA, KAT reviews ↗ 3.31 3.31 1,124 2 48% average not teaching it
VAZQUEZ-SALAZAR, ALBERTO reviews ↗ 3.61 3.62 419 2 77% - not teaching it
CLARKE, STEVEN G reviews ↗ 2.93 2.89 200 1 37% very light not teaching it
CLARKE, CATHERINE FREITAG reviews ↗ 2.93 2.89 200 1 37% average not teaching it
LEE, ANTHONY reviews ↗ 3.10 3.08 166 1 41% - not teaching it
GOBER, JAMES W reviews ↗ 3.31 3.31 12 · 1 50% average not teaching it
Why Predicted is not the Raw average

“Predicted” is shrunk toward the course average, which is itself shrunk toward the department, so an instructor with a handful of students sits near the course mean rather than topping the list.

Grade records describe outcomes. For what a course is like to take, read student reviews written on dibs below or follow the separate external review link.

Reviews for CHEM 153A

Workload and assignments

Work types reported in BruinWalk reviews of this course, across recorded instructors and terms. They may differ from this term's syllabus.

dibs has read this course’s reviews and none of them say what kind of work it sets, so dibs has nothing to show rather than a guess. Read from 246 reviews 27 days ago. That is the reviewers being silent, and not a course that sets no work.

Read the source reviews

What comes first

The chain dibs can see is 4 courses long before CHEM 153A. This is a floor, not a deadline: dibs has not read a class page for CHEM 20B, so the real chain can only be longer than this, never shorter.

Counted in courses rather than quarters: dibs does not know which of them a department lets you take together.

In Falls

Ran in 4 of the last 4 Falls.

From the terms dibs holds, which start in Fall 2021 and exclude summer. A department can run a course in a quarter it never has before.

From the registrar's catalog

Lecture, four hours; discussion, one hour. Requisite: course 14D or 30B, with grade of C- or better. Recommended: Life Sciences 2, 3, and 23L, or 7A. Structure of proteins, carbohydrates, and lipids; enzyme catalysis and principles of metabolism, including glycolysis, citric acid cycle, and oxidative phosphorylation. P/NP or letter grading.

Sections in Fall 2026

You enroll in the discussion, not the lecture, so a discussion's status is the one that decides whether you get in. A lecture can read open while every discussion under it is full.

Seat counts as of : the oldest of these 26 readings. Seat readings are snapshots, not live availability. Their timestamps show when dibs last checked.

Final enrollment, averaged across each term's sections: between 181 and 350 a term over 12 terms, summer excluded, most recently 300 in Fall 2025. That is the shape across years, not this term, which is above.

From the people who took it

Student reviews

What taking CHEM 153A was like: the work, the teaching, and what students wish they’d known.

Write a review

Your experience could be the first.

No student reviews are available to read on dibs for this course yet. Took it? Tell the next person what helped, what was hard, and how you spent your time.

Looking for more perspectives?

External reviews are separate and do not count toward the dibs rating.

Read reviews on BruinWalk

Community guidelines

Seats over time in Fall 2026

How each lecture has filled since dibs first saw it. This course runs 2 lectures; the legend under the chart picks one.

A dot is a reading where something moved: the seat count, the status, or the waitlist.

What a flat run means, and where a line starts

Flat between dots means it did not drift, it held and then jumped, and a line starts when dibs first saw that lecture rather than reaching back before it existed. A lecture that has never moved draws a flat line across the whole window, and one with two or three readings draws a line joining them, which is too few to read a trend from.

Lec 1 · Lannan, R. and Wilson, P. · 345 of 350 enrolled

Nothing read since 2 Oct, 3 hours ago. Over about 1 month before that, filled by 85.

345 of 350 · 5 left in its discussions
18 Aug 18:409 Sep 23:412 Oct 04:42 · 3 hours ago
dibs read 168 of the 517 hours its hourly record covers, 32%, and did not look in 349. dibs had no hourly record before 10 Sep, which is the other 550 of 1067 plotted.345 of 350 enrolled at the newest reading, 3 hours ago, with 5 left in its discussions. Seats from 18 Aug 18:40 to 2 Oct 04:42, 260 to 345. dibs read 168 of the 517 hours its hourly record here covers, 32%. An hour marked as read confirms a check, not continuous monitoring. That check recorded no change; changes between checks may be missed. For 349 hours dibs was keeping a record and did not reach this section. Nothing before 10 September at 16:00, where this section's record starts, has a read either way, which is 550 hours of this window. Where the drawing is faint or broken, that never means the readings are doubtful. It means the stretch between them is unaccounted for.

Lec 2 · Lannan, R. and Wang, S. · 338 of 350 enrolled

Nothing read since 2 Oct, 3 hours ago. Over about 1 month before that, filled by 129.

338 of 350 · 12 left in its discussions
18 Aug 18:409 Sep 23:412 Oct 04:42 · 3 hours ago
dibs read 168 of the 517 hours its hourly record covers, 32%, and did not look in 349. dibs had no hourly record before 10 Sep, which is the other 550 of 1067 plotted.338 of 350 enrolled at the newest reading, 3 hours ago, with 12 left in its discussions. Seats from 18 Aug 18:40 to 2 Oct 04:42, 209 to 338. dibs read 168 of the 517 hours its hourly record here covers, 32%. An hour marked as read confirms a check, not continuous monitoring. That check recorded no change; changes between checks may be missed. For 349 hours dibs was keeping a record and did not reach this section. Nothing before 10 September at 16:00, where this section's record starts, has a read either way, which is 550 hours of this window. Where the drawing is faint or broken, that never means the readings are doubtful. It means the stretch between them is unaccounted for.
How readings and alerts work

A reading and an hourly record are different things, and most charts here hold more of the second missing than present. dibs has taken readings of a section since long before it began keeping an hour-by-hour log of when it looked, so the empty stretches are dibs saying it was not keeping that log yet, not that it looked and found nothing. That is the age of the record and not a fault.

Seat counts show the last successful read, not live availability. Refreshes can be delayed by request limits or upstream interruptions. Watched sections receive priority, but an hourly update for every section is not guaranteed.

The registrar can change a seat count between our checks. Alerts depend on dibs detecting an opening and completing delivery; a quiet watch does not prove that no seat opened. Check the registrar before enrolling.