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Flashcards in Eukaryotic Cells Deck (40)
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1

What are the 4 basic tenets of cell theory?

1. all living things are composed of cells
2. cell is the basic functional unit of life
3. cells arise only from preexisting cells
4. cells carry genetic information in the form of DNA

2

Are viruses considered living organisms?

No because they are not able to reproduce on their own -- replicate by invading other organisms -- and genetic information is in the form of RNA

3

What organelles are found in a eukaryotic cell?

*membrane-bound organelles*
-endocytotic vesicle
-centrioles
-nucleolus
-nucleus
-golgi apparatus
-ER
-ribosomes
-cytoplasm
-mitochondria
-lysosomes
-nuclear membrane
-cell membrane

4

Describe the cell membrane

-phospholipid bilayer
-surface is hydrophilic (electrostatic interaction with aqueous environment inside and outside of cell)
-inner layer is hydrophobic (provides highly selective barrier between inside and outside of cell)

5

Cytosol

allows for diffusion of molecules inside of the cell

6

Nucleus

-contains genetic material for replication
-surrounded by the nuclear membrane/envelope (double membrane that keeps nuclear environment distinct from cytoplasm)

7

What are nuclear pores?

-located in the nuclear membrane/envelope
-allows for selective 2-way exchange of material between cytoplasm and nucleus

8

What is the nucleolus?

-subsection of the nucleus
-where rRNA is synthesized
-takes of 25% of the volume of the entire nucleus

9

Mitochondria

-powerhouse of the cell
-evolved from an anaerobic prokaryote engulfing an aerobic prokaryote and establishing a symbiotic relationship
-can kill the cell by releasing enzymes from ETC
-semiautonomous (contain some of their own genes and replicate independently of nucleus via binary fission)
-cytoplasmic/extranuclear inheritance (transmission of genetic material independent of the nucleus)
-has its own DNA
-inherit all of our mitochondria from maternal parent

10

Explain the structure/function of the mitochondria

-outer membrane: serves as barrier between cytosol and inner mitochondrial environment
-inner membrane: contains numerous infoldings called cristae that contain molecules/enzymes necessary for ETC and increase SA for ETC enzymes; location of ETC
-intermembrane space: space btw inner and outer membranes
-mitochondrial matrix: space inside of the inner membrane, where all metabolic pathways occur
-pumping of protons from matrix to intermembrane space establishes the proton-motive force and allows for generation of ATP during oxidative phosphorylation

11

Lysosomes

-membrane bound organelle containing hydrolytic enzymes that break down substances from endocytosis and cellular waste
-involved in retrograde transport
-function in conjunction with endosomes
-release of hydrolytic enzymes into cell leads to autolysis

12

Endosomes

transport, package, and sort cell material traveling to/from the membrane

13

Endoplasmic Reticulum

-series of interconnected membranes that are contiguous with the nuclear envelope
-has a double membrane that is folded into invaginations

14

Rough ER

contains ribosomes which allow translation of proteins destined for secretion directly into lumen of ER

15

Smooth ER

-lacks ribosomes
-utilized for lipid synthesis (ex. phospholipids in cell membrane)
-detox of drugs/poisons
-transports proteins from rough ER to golgi

16

Golgi Apparatus

-contains stacked membrane-bound sacs
-receives materials from ER contained in vesicles
-modifies products via addition of carbs and phosphates and sulfates
-can modify products via introduction of signal sequences
-modifies cell products -> repackages products in vesicles -> transfer vesicles to correct cell location

17

How are products released from a cell?

exocytosis -- secretory vesicle from golgi merges with cell membrane and releases its contents

18

Peroxisomes

-contain hydrogen peroxide which breaks down long chain fatty acids via beta oxidation
-participate in synthesis of phospholipids and contain some enzymes involved in pentose phosphate pathway
-specialized metabolic functions that produce H2O2 as a bi-product which is converted into water

19

Cytoskeleton

-consists of microfilaments, microtubules and intermediate filaments
-provides structure to the cell, maintains cell shape, and provides conduit for transport of materials around cell

20

Microfilaments

-made of solid polymerized rods of actin
-play a role in cytokinesis by forming a cleavage furrow

21

Actin Filaments

-make-up microfilaments
-organized into bundles/networks
-resistant to compression and fracture
-use ATP to generate force for movement by interacting with myosin

22

Microtubules

-hollow polymers of tubulin proteins
-provide primary pathways for motor proteins kinesin and dyenin to carry vesicles

23

Cilia

-mobile structure compose of microtubules
-involved in movement of materials along surface of cell
-line the respiratory tract

24

Flagella

-motile structure composed of microtubules
-involved in movement of cell itself (ex. sperm)

25

9+2 Structure

-structure with 9 pairs of microtubules forming an outer ring with 2 microtubules in the center
-only seen in eukaryotic organelles of motility (ex. cilia, flagella)

26

Centrioles

-found in the centrosome
-organizing centers for microtubules
-structured as 9 triplets of microtubules with a hollow center

27

Intermediate Filaments

-group of filamentous proteins (ex. keratin, desmin, vimentin, lamins)
-involved in cell-cell adhesion or maintenance of integrity of cytoskeleton
-make cell structure rigid
-help anchor organelles like the nucleus

28

What are the 4 different types of tissues?

-epithelial
-connective
-muscle
-nervous

29

Epithelial Tissue

-covers body and lines body cavities
-provides means for protection against pathogen invasion
-cells are tightly joined to each other and to an underlying layer of connective tissue called the basement membrane
-cells are often polarized with one side facing a lumen (inside of organ) and other side facing blood vessels/structural cells
-can be classified by layer (simple, stratified, pseudostratified) or shape (cuboidal, columnar, squamous)

30

Simple Epithelia

have one layer of cells