Cell Structure and Function - Part 2 Flashcards Preview

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Flashcards in Cell Structure and Function - Part 2 Deck (17):
1

What are ribosomes

formed from rRNA; stain with hemotoxilin. They synthesize proteins. Can be free or bound to rough ER

2

What happens to ribosomes that go to rough ER

Proteins bound for secretion; mRNA comes out and ribosome finds it and has code that it goes to rough ER.

3

What is the rough ER

Contains ribosomes on cytoplasmic surface
-Proteins that are destined for the membrane, lysosomes, or secretion
-form cristae
-if a protein

4

What is smooth ER

-Form tubule structures
-synthesis of lipids, and steroids
-degradation of toxic compounds
-production of HCl in stomach
-Sequesters Ca++ in muscle

5

What is golgi apparatus

membrane bound organele
-further modifies and packages proteins made by rough ER

trans phase: package and take proteins to lysosoms, membranes, secretory vesicles, or constitutive secretion (default pathway)

6

What is the pathway for protein synthesis and transport

1. mRNA comes from nucleus to Rough ER
2. Gets glycosylated in rough ER
3. vesicles transport proteins to cis face of golgi apparatus
4. they get further modified as they move through golgi apparatus
5. At trans face they get sorted and packaged into vesicles to travel to their final destination.

7

what are lysosomes

vesicles containing hydrolytic enzymes synthesized in rough ER/golgi apparatus
-breakdown proteins, lipisd, nucleic acids
-very acidic

8

what are peroxisomes

membrane bound small envmt
-oxidize fatty acids
-contain hydrogen peroxide and catalase
-use enzymatic staining

9

what are non membranous organelles

1. ribosomes
2. all of the components of the cytoskeleton

10

What is actin

thin filament
-involved in cell shape, movement and structural support
-form globules; G-actin: soluble monomer subnunit.
-F-actin: double stranded helical filaments; have polarity

11

What are microtubles

largest component of cytoskeleton; Each tubule is formed from 13 protofiliaments
-Tubulin dimersS: 1 alpha and 1 beta
-Have polarity
-Dyneins move toward center of cell (+)
-Kinesins move toward periphery of cell (-)

12

What are specialized structures formed by microtubuls

Cilia and Flagella
-Axoneme: 9 microtubule doublets around 2 central microtubules

13

Each doublet is formed from an A- tubule and a B tubule. A tubule is formed from ___protofilaments. B- tubule is formed from ___ or ___protofilaments

13, 10 or 11

14

What support microtubules

Centrosomes: Support
mitotic spindles and help with sequesteration of sister chromatids during mitosis
Centrioles: 9 triplets of microtubules without central microtubules; continuous with axoneme

15

____filaments are another component of the cytoskeleton

Intermediate filaments: provide tensile strength to the cell and form keratins, vimentins, neurofilaments and lamins
-Dont have polarity
-Subunit is a long alpha helical chain formed by a dimer which form antiparralel tetramers.

16

What are components of the cell cycle

1. G0; Restriction checkpoint: where most cells are just sitting, or stem cell thats not actively dividing. Most cells in our body
2. G1 phase: cell growth.
3. S phase: Replicates
4. G2 phase: undergoes any DNA damage repair and continues to grow
5. mitosis

17

mitosis

1. prophase: chromosomes condense. nuclear envolope degrades
2. metaphase: microtubules form and chromosomes align on metaphase plate
3. anaphase: sister chromatids are separated toward poles
4. telophase: nuclear envolope reforms; chromosomes decondense