Lecture 5: Cell Structure Flashcards
1
Q
all cells have the four following (describe their function too):
A
- plasma membrane: selectively permeable barrier
- nucleic acid: store, transmit, and process info
- proteins: perform cell functions
- carbohydrates: provide chemical energy, carbon, suport, and identity (cell markers)
2
Q
prokaryotes vs eukaryotes
A
- prokaryotes: unicellular organism with no nucleus/ other membrane bound organelles (bacteria or archaea)
- eukaryotes: have nucleus , mitochondria, and other organelles
3
Q
archaea
A
- genetically and biochemically different from bacteria; organism that lives in extreme environments
4
Q
Fill in the blank and answer: animal and plant cells are ___ _______ than bacteria. What are the advantages of small cells and advantages of large cells?
A
- ~10x larger
- small cells advantage: large SA:V ratio; faster exchange in/ out of cell. shorter transport distance
- large cells advantage: more space, more storage, more compartments
5
Q
prokaryotic cells
- explain walls
- size
- surrounded by what
- inside: cytoplasm (4)
A
- protective cell walls made of amino acid/ sugar polymer (peptidoglycan)
- 1-10um
- cells are surrounded by a membrane
- inside: chromosomes (condensed DNA), plasmids (auxillary DNA), ribosomes (for protein synthesis), intracellular fluid aka cytosol (made of proteins, ions, metabolites, etc)
6
Q
eukaryotic cells
- size
- compartmentalized
A
- 5-100um
- compartmentalised: nucleus and other organelles surrounded by membrane in the cytoplasm
7
Q
what are the advantages of having compartments within a cell?
A
- allows for more specialization (and more functions)
- you can separate incompatible chemical reactions
- smaller units with more concentrated content
8
Q
can you identify the organelles in the google doc?
A
- see google doc
9
Q
nucleus
- how many membranes
- function
- nucleolus
- nuclear lamina
A
- double membrane with pores (nuclear envelope)
- contain DNA in chromosomes
- nucleolus makes RNA
- nuclear lamina: lattice structure for support
10
Q
endoplasmic reticulum
- structure/shape (made from what?)
- rough ER
- smooth ER
- lumen
A
- nuclear envelope extends into cytoplasm for the sac-like organelle
- rough: studded with ribosomes; site of protein synthesis and folding
- smooth: extends further into cell and site of membrane lipid synthesis and assembly of membrane (lipid processing centre)
- lumen: inside space in the ER
11
Q
golgi apparatus
- structure
- function
- cisterna
- trans vs cis golgi
A
- stacks of flat sacs and free vesicles
- site of protein modifications (process, sort, ship)
- cisterna: flattened membrane discs that make up the golgi apparatus stacks
- proteins move from the ER to the plasma membrane side (trans golgi)
- cis golgi: nuclear side
12
Q
lysosome
- function
- hydrolases
- hydrolysis
A
- aka recycling centre where proteins, lipids, carbs, and nucleic acids are all broken down into compartments (amino acids, fatty acids, sugars, nucleotides)
- hydrolases: digestive enzymes
- hydrolysis: occurs in lysosome when material is digested; breakdown of compound due to reaction with water
13
Q
endomembrane system
- key players (3)
A
- although they’re separate, they’re connected by the system
- content moves along in vesicles through (see notes)
14
Q
peroxisomes
- structure
- origin
- function
A
- membrane enclosed structures that originate from ER vesicle
- break down some lipids and other components by oxidation
- oxidation results in production of hydrogen peroxide as a by product (toxic)
- peroxisomes protect cell against H2O2 through compartmentalization; catalase breaks down H2O2
15
Q
mitochondria
- membrane
- cristae
- mitochondrial matrix
- function
- has their own?
A
- double membrane
- folded saclike structure that extends inward to increase SA (cristae); area between cristae called mitochondrial matrix
- powerhouse of the cell
- produce ATP
- have their own DNA that encode of their protein but most are imported
