Cell structure and function basics

Question 1

RNA

Answer 1

DNA is the heritable material with RNA being the messenger and proteins the worker. DNA codes for RNA codes for proteins

Question 2

Difference between prokaryote and eukaryote

Answer 2

eukaryote have membrane bound organelles and are much larger. pro don’t have a membrane bound nucleus. both have DNA, RNA, Proteins, and ribosomes

Question 3

Cytoplasm

Answer 3

everything in plasma membrane (incl. organelles) except for nucleus. the fluid is cytosol

Question 4

major organelles

Answer 4

endomembrane system:
- nucleus
- nucleolus
- ER (RER + SER)
- Golgi apparatus
- lysosomes
Other:
- mitochondria
- ribosomes
- flagella
- Plasma membrane
- vesicles/lysosomes/peroxisome/etc,

Question 5

Plasma membrane

Answer 5

physical barrier, double layer of phsopholipids. tails dislike water so are inside the bilayer

Question 6

plasma membrane proteins

Answer 6

integral: embedded partially of fully (transmembrane)
peripheral: associated but not embedded
amphipathic: hydrophilic and phobic regions corresponding to where they interact with the bilayer

Question 7

PM protein functions

Answer 7

transport: channels, transporters, can be selective, gated, general, or not
enzymatic: chemical reactions and can be apart of a team
signal transduction: molecules bind to receptor and then cause signal to pass through via shape change
cell-cell recognition: GAGs used as molecular signatures
junctions: adherens and the like
attatchement: connection to ECM and cytoskeleton

Question 8

nucleus

Answer 8

houses dna, make rna and ribosomes. douple. molecule segregatuon to allow tempora and spatial control of cell function. lipid bilayer continuous to RER with controlled access.

Question 9

DNA in nucleus

Answer 9

wrapped around 8 histones to form nucleosomes which are collectively known as chromatin. during cell division chromatin condenses to fibers and then loops, then chromosomes

Question 10

ribosomes

Answer 10

translate proteins (produce), found free in cytoplasm (non endomembrane destinations) and in RER (non cytosolic proteins)

Question 11

RER

Answer 11

makes secreted, membrane, and organelle proteins. makes vesicles to transport proteins to golgi. continuous with Nuclear envelope

Question 12

SER

Answer 12

no ribosomes. houses proteins and enzymes. makes lipids, storage of cell specific proteins

Question 13

golgi

Answer 13

receives vesicles from RER. made of sacs caller cisternae. modifies proteins further, package and transport

Question 14

lysosome

Answer 14

digestion of things in cell (things that enter; autophagy - organelles; entire cells - autolysis). formed by golgi

Question 15

mitochondria

Answer 15

ATP generation. Outer and inner membrane. matrix and cristae. hydrolysis of ATP releases energy

Question 16

cytoskeleton

Answer 16

microfilaments: ~7nm. bear tension and weight. dynamic
intermediate filaments: 8-12nm bear tension and weight. scaffold, less dynamic
microtubules: 25nm. central lumen, support cell shape and size but allow movement. guide for organelles. assembled and disassembled as needed so are dynamic