1. Cell Structure

Question 1

cytoplasm

1) what are the two main components?
2) where is it?
3) what does it look and move like?

Answer 1

1) cytosol + organelles
2) fills interior of cell
3) transparent, water-based gel behavior

Question 2

what is a cell?

Answer 2

the basic unit from which living organisms are made

aquesous solution of organic molecules

membrane enclosed

Question 3

integral membrane proteins

Answer 3

embedded in one side of lipid bilayer

Question 4

what is a tissue?

Answer 4

assembly of specialized cells serving a general function

Question 5

cytoskeleton

1) in general what is it?
2) what does it give the cell?
3) what are the three components/ types?

Answer 5

1) protein filaments in cytoplasm
2) give polarized shape, directed movement
3) actin filaments, microtubules, intermediate filaments

Question 6

Ribosomes

1) what is a ribosome composed of?
2) what is it’s primary function?
3) where do they occur?
4) what do they stain?

Answer 6

1) ribosomal RNA and proteins that associate with mRNA
2) catalyzes the synthesis of proteins
3) free clusters of polyribosomes or associated with ER
4) basophilic (blue/purple)

Question 7

what reinforces the plasma membrane?

what is it made of?

what other cell structures can it make?

Answer 7

the cell cortex

specialized layer of cytoplasm with a meshwork of actin

also makes microvilli, ridges, dents

Question 8

lipid bilayer

1) where is it?
2) what is it made of?
3) how are they oriented?
4) what is a major function?

Answer 8

leaflet between two protein coats in plasma membrane

phospholipid molecules

hydrophobic tails inwards, hydrophilic heads outwards

permeability barrier

Question 9

transmembrane proteins

Answer 9

proteins embedded in lipid bilayer that span the membrane

Question 10

glycocalyx

what is it?

what texture does it appear?

what are it’s (4) functions?

Answer 10

sugar coating of oligosaccharides and polysaccharides

looks "fuzzy"

protects and lubricates, used in recognition and adhesion

Question 11

proteasome

1) what is a proteasome?
2) what must a protein be marked with to be recognized?
3) what is the structure of a proteasome?
4) which part of the structure recognizes ubiquitin?
5) what does the proteasome use for energy?
6) what are the functions of the regulatory particle and core?

Answer 11

1) a large protease complex in cytosol that degrades intracellular proteins
2) multiple ubiquitin proteins
3) a 4 ringed core particle and 2 regulatory particles
4) the regulatory particle
5) ATP
6) the regulatory particle unwinds the protein and the core breaks the protein apart

Question 12

what is a system?

Answer 12

several organs with related functions

Question 13

1) what is the ER?
2) what is it’s function?
3) What does RER have that SER doesn’t?
4) What’s the function of RER?
5) What’s the function of SER?
6) How do RER and SER stain?

Answer 13

1) labyrintine, membrane bounded compartment in cytoplasm
2) secretes lipids and makes membrane bound proteins
3) associated ribosomes
4) synthesizing secreted and membrane-bound proteins
5) synthesizing lipids, metabolizing lipid soluble substances, regulating Ca
6) RER stains basophilically, SER doesn’t stain

Question 14

mitochondria

1) what did mitochondria arise from?
2) what is their appearance?
3) what are the inner membrane folds called and what do they do?
4) what is located on the outer membrane?
5) what does the matrix consist of?
6) what are the 3 functions of the matrix granules?

Answer 14

1) bacteria with their own DNA and RNA
2) rod or spherical with a double membrane
3) cristae, increase surface area for metabolic activites and the site of enzymes associated with electron transport and phosphorylation
4) proteins for mitochondrial lipid synthesis
5) the internal space filled with a high concentration of enzymes for pyruvate oxidation and the citric acid cycle
6) ATP production and electron transport, bind cations like Ca, apoptosis cascade

Question 15

what is an organ?

Answer 15

two or more tissues

combined into functional units

Question 16

1) What is the golgi’s function?
2) what are the flat, membrane bound sacs?
3) What are the two faces and where are they?
4) how is transport carried out?

Answer 16

1) lipids and proteins made in ER are modified and sorted
2) cisternae
3) Cis face, entry face, forming face (adjacent to ER)

trans face, exit face, (concave towards plasma membrane)

4) by transport vesicles

Question 17

peripheral membrane proteins

Answer 17

proteins that aren't embedded in the lipid bilayer

sit on top of layer

Question 18

plasma membrane

1) what and where is it?
2) can you see it on LM?
3) what is the functional part?

Answer 18

external thin fatty film, surrounds the cell

not seen on LM

membrane functions carried out by membrane proteins, some modified to glycolipids

Question 19

nucleus

1) what is it?
2) Describe the membranes

Answer 19

1) prominent organelle in the cell that contains genetic material
2) two concentric membranes = nuclear envelope

Question 20

1) what are lysosomes?
2) what is their function?
3) what are the three pathways involving lysosomes?
4) what are the lysosome membrane proteins highly glycosylated?
5) what is a secondary lysosome?
6) what is autolysis?

Answer 20

1) membranous sacs of hydrolytic enzymes
2) control intracellular digestion of extracellular material and worn out organelles
3) phagocytosis - internalize large particles that merge with a lysosome

autophagocytosis - degradation of internal organelles

hydrolitic enzymes can be secreted outside the cell

4) the sugars cover the protein surface facing the lumen and protect it from being digested
5) when an endosome fuses with a primary lysosome
6) when lysosomal membranes rupture and release their hydrolytic enzymes inside the cell

Question 21

signaling sequence

1) what else is it called?
2) what is it?
3) what happens to the sequence once it's been sorted?
4) what is the important part of the sequence?

Answer 21

1) signal peptide or targeting sequence
2) short amino acid sequence that directs a protein to a specific location or organelle
3) usually removed from the protein
4) the charged amino acids