By having a deeper, better understanding of the literature you're reading in class, you will be able to provide educated and well thought comments during class discussions. By knowing what you've read, you'll have more confidence which may influence whether or not you participate in class.
Generally, 20% of your grade is based on class participation (although this varies from class to class and teacher to teacher). This includes attendance, looking attentive in class and participation in class discussions.
The way we comprehend what we're reading comes to us based on our individual learning styles. There are a few things you can do to help yourself remember/retain what you're reading.
The different things you do to help yourself retain and comprehend what you're reading is considered active reading. This means that you are going beyond the required reading, and taking extra steps to help ensure your comprehension of the text.
One thing that I find helpful is taking detailed notes (or brief notes) on the things I think I may have questions about, or may see on a quiz later. Sometimes, I just write down the things that interest me - relevant to class or not. This comes in handy for paper topics.
Another thing I like to do is write/mark in my books (marginalia) to help me sort through what I'm reading. This also comes in handy in the event that I need evidence for a paper.
Writing a brief summary of each chapter, or reading out loud can also be very helpful. These things help you to organize your thoughts.
Source: myself
This video discusses a few active reading tips, and why they are helpful. Please feel free to share the things that help you retain what you're reading!!
Source: featuring: Will in the World, Romeo and Juliet, myself and my notes!
"Really like this and would recommend for incoming freshmen (high school or college). Great work! "
"Great information for students to learn."