chapter 5.docx

4 Pages
83 Views
Unlock Document

Department
Biological Science
Course
BISC 160
Professor
Dr.Beckie Symula
Semester
Fall

Description
Chapter 5 5.2 What features characterize prokaryotic cells?  Prokaryotic cells share certain features o Plasma membrane separates it from external environment o Nucleoid contains DNA o Cytoplasm: the rest of the cell  Cytosol: mainly water, contains dissolved ions, small molecules, and soluble macromolecules such as proteins  Ribosomes: made of RNA and proteins, 25 nm, protein synthesis  Specialized features are found in some prokaryotes o Cell walls  In bacteria but not archaea  Contain peptidoglycan  Slimy layer called a capsule encloses the cell wall and keep cells from drying out  Capsule is not essential to prokaryotic life, and most prokaryotes produce no capsule o Internal membranes  cyanobacteria and some other bacteria carry out photosynthesis  Internal membrane systems contain molecules needed for photosynthesis  Other prokaryotes have internal membrane folds that function in cell division or in various energy- releasing reactions o Flagella and Pili  Some prokaryotes swim by flagella  Made of the protein flagellin Cause the movement (propeller motion) of a cell  Pili is made of protein that are hairlike and shorter, used for adherence  Fimbriae are similar to pili ut shorter and help cells adhere to surfaces such as animal cells for food and protection o Cytoskeleton  Rod-shaped bacteria have a helical network of filamentous structures that extend down the length of the cell just inside the plasma membrane  Made of proteins and are similar to actin in eukaryotic cells 2 [Type text] 5.3 What features characterize eukaryotic cells?  Compartmentalization is the key to eukaryotic cell function o Nucleus contains DNA; first steps in gene replication take place here o Mitochondria converts energy stored in bonds of carbohydrates and fatty acids into ATP o Endoplasmic reticulum and Golgi apparatus synthesize some proteins by ribosomes and package them and send them to locations in the cells o Lysosomes and vacuoles are cellular digestive systems by hydrolyzing large molecules o Chloroplasts perform photosynthesis  Some structures are not considered organelles because they lack membranes: o Ribosomes o Cytoskeleton (made up of protein-based filaments) o Extracellular matrix  Ribosomes are factories for protein synthesis o Composed of two different-sized subunits o Eukaryotic ribosomes are generally larger, but structure of prokaryotic ribosomes is better understood o rRNA and 50 different protein molecules which are noncovalently bound to the rRNA o in prokaryotic cells, ribosomes float freely in the cytoplasm o in eukaryotic cells they are in the cytoplasm attached to ER or inside mitochondria and chloroplasts  The nucleus contains most of the genetic information o Nucleus is the largest organelle o Location of DNA and site of DNA replication o Gene transcription is turned on or off o The Nucleolus is where ribosomes being to be assembled from RNA and proteins o Two membranes surround the nucleus called the nuclear envelope  Separates the genetic material from the cytoplasm.  Functionally it separates DNA transcription from translation which occurs in cytoplasm o Nuclear localization signal
More Less

Related notes for BISC 160

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit