Biol 190 Unit 2 Chapter 9

studied byStudied by 1 person
5.0(1)
Get a hint
Hint

What are organelles?

1 / 88

flashcard set

Earn XP

Description and Tags

Biology

89 Terms

1

What are organelles?

"Little organs" usually enclosed within their own lipid bilayer; specialized unit in a cell that has its own specific function; only found in eukaryotic cells

New cards
2

What are the two main roles of an organelle’s lipid bilayer?

  1. Separate different chemical reactions within the cells (especially incompatible reactions)

  2. Increase efficiency of reactions or transport of molecules

New cards
3

What is the nucleus?

-"Cell's control center"

-Largest organelle inside cell

-contains the genetic material (DNA/the blueprint of life)

-DNA is complexed with proteins (i.e. chromatin or chromosomes)

-site of DNA replication and transcription

New cards
4

What is the nucleolus?

-Center of nucleus

-location for ribosome assembly

New cards
5

What is the nuclear envelope?

Double membrane that surrounds the nucleus (protection)

New cards
6

What is the nuclear pore?

Channels in the nuclear envelope (allows things in & out)

New cards
7

Does DNA leave through the nuclear pore?

No, DNA stays within the pore, but RNA and ribosome do to the cytoplasm

New cards
8

Are ribosomes considered organelles?

No, it lacks a phospholipid bilayer and found in eukaryotic and prokaryotic cells

New cards
9

What are ribosomes?

The site of translation/ protein synthesis; found in two locations:

-in the cytosol (free ribosomes= no organelle is needed)

-Endoplasmic reticulum (bound to ER)

New cards
10

What is the structure of ribosomes?

Large subunit bound to small subunit

New cards
11

What is the function of ribosomes?

Gene expression-> (more specifically) the step of translation

New cards
12

What is the endomembrane system?

Series of physically connected or vesicle-connected membranes that work together in protein synthesis, protein enfolding, and protein transportation.

New cards
13

What is the function of the endomembrane system?

-Regulates protein traffic

-Performs metabolic functions

New cards
14

What membranes are involved in the endomembrane system?

  1. Nuclear envelope

  2. endoplasmic reticulum (ER)

  3. Golgi apparatus

  4. lysosomes

  5. vacuoles

  6. plasma membrane

New cards
15

What are vesicles?

Sacs made of membrane

New cards
16

What is the endoplasmic reticulum?

"Biosynthetic Factory" ; the ER membrane is continuous with the nuclear envelope; two regions

New cards
17

What are the two distinct regions of ER?

-Smooth ER: lacks ribosomes

-Rough ER: surface is studded with ribosomes

New cards
18

What is the function of the smooth ER?

  1. Site of lipid synthesis (name some lipids)

  2. Metabolizes and stores glycogen

  3. Toxin and poison breakdown (particularly in the liver)

  4. An internal storage site for ions (e.g. Ca2+ in muscle)

New cards
19

What is the function of the rough ER?

-Has bound ribosomes, which secrete glycoproteins

-distributes transport vesicles

-a membrane factory for the cell

New cards
20

What are glycoproteins?

Proteins covalently bonded to carbohydrates

New cards
21

What are transport vesicles?

Secretory proteins surrounded by membranes

New cards
22

What is the lumen?

Space between membrane within rough ER

New cards
23

What are the steps performed in the rough ER?

  1. Polypeptide synthesized by ribosome

  2. Polypeptide folds into protein and is modified

  3. Transport vesicle "buds off"

  4. Receptor proteins tell the cell where to ship the contents

New cards
24

What happens to the transport vesicle?

Transport vesicles leave the ER and reach the Golgi

New cards
25

What is the Golgi apparatus?

A stack of single membranes (cisternae)

New cards
26

Define cisternae.

Flattened membranous sacs

New cards
27

What is the function of the Golgi apparatus?

An assembly line:

1. Modifies products of the ER

a. Packages, stores, and distributes proteins for their final destination

b. Adds protein modifications, like carbohydrate groups

2. Creates lysosomes

3. Makes polysaccharides for plant cell walls

New cards
28

What is the receiving side of the Golgi apparatus?

Cis face

New cards
29

What is the shipping side of the Golgi apparatus?

Trans face

New cards
30

Where does the functional protein from the Golgi apparatus go?

The functional protein (inside a transport vesicle) stay within the cytoplasm of the creating cell, creates a lysosome, or transport vesicle fuses with cell membrane to release the protein out (secretion)

New cards
31

What are lysosomes?

Membranous sacs filled with digestive enzymes; inactive until they fuse with another vesicle

New cards
32

What can a lysosome hydrolyze?

Lysosome enzymes hydrolyze all 4 macromolecules

New cards
33

What is the function of lysosomes?

Cleanup and recycle- both of cellular and foreign materials: two ideas-> phagocytosis and autophagy

New cards
34

What is the first function (idea) of lysosomes?

Phagocytosis: eating extracellular items

-Protection from bacteria

-Food metabolism by forming food vacuoles

New cards
35

What is the second function (idea) of lysosomes?

Autophagy (self-eating) -Recycles organelles and macromolecules

New cards
36

What is the function of peroxisomes?

Breakdown of long chain fatty acids through beta-oxidation; metabolism creates H2O2 (toxic peroxides), so converts them to water

New cards
37

What are peroxisomes important in?

Metabolism of fatty acids

New cards
38

Where do peroxisomes come from?

Buds off the ER instead of the Golgi (like lysosomes); found in most eukaryotic cells

New cards
39

What are glyoxysomes?

Specialized peroxisomes found only in plants, aid breakdown of lipids into carbohydrates in growing seedlings

New cards
40

What organelles harvest energy?

Mitochondria and chloroplasts harvest energy and contain their own DNA and ribosomes

New cards
41

What is mitochondria?

All eukaryotic cells, is the site of cellular respiration

New cards
42

What are chloroplasts in?

Plants and other photosynthesizers

New cards
43

What is the theory of endosymbiosis?

Mitochondria and chloroplasts evolved after a prokaryotic cell was engulfed by a larger cell and lived inside; engulfed cell provided its host with advantages because of its special metabolic activities

New cards
44

Define selective advantage.

The characteristic of an organism that enables it to survive better than other neighboring organisms

New cards
45

What is the evidence for the endosymbiont theory?

  1. Circular DNA molecules

  2. Contain free ribosomes with similar subunit

  3. Enveloped by a double membrane

  4. Grow and reproduce somewhat independently in cells

New cards
46

What is the mitochondria?

"Powerhouse of the cell" for energy production (ATP)

New cards
47

What are the characteristics of DNA?

Can divide independently-> own DNA and ribosomes; # in a cell can vary, 1-10,000; important for energy metabolism

New cards
48

What is the structure of the mitochondria?

Has 2 membranes inner highly folded

New cards
49
<p>Label the mitochondria.</p>

Label the mitochondria.

A. Outer membrane B. Inner membrane C. Intermembrane space D. Matrix

New cards
50

What is mitochondrial disease (MD)?

Commonly linked to diseases of aging

New cards
51

What is the primary cause of mitochondrial disease (MD)?

A defect in nuclear DNA (nDNA) encoding for protein or in mitochondrial DNA (mtDNA)

New cards
52

Where does mtDNA come from?

Primarily inherited from the mother's egg, expressing ~30 proteins not expressed

New cards
53

How many individuals have mitochondrial disease (MD)?

1 in 200 individuals have a mitochondrial DNA mutation that may lead to disease

New cards
54

What are chloroplasts?

Site of photosynthesis; have ribosomes-> can divide independently

New cards
55

What is the function of chloroplasts?

Convert light energy to chemical through photosynthesis, involving the green pigment chlorophyll

New cards
56

What type of kingdoms have chloroplasts?

Plantae and protista (never animalia of fungi-> decomposers)

New cards
57

Are prokaryotes photosynthetic?

Yes, only need chlorophyll to perform photosynthesis

New cards
58

What are vacuoles?

Storage organelle

New cards
59

What is the function of vacuoles?

Store pigment attracting pollinators and storage of toxins and chemicals (opium)

New cards
60

What are food vacuoles formed by?

Phagocytosis

New cards
61

Where are vacuoles found?

Mostly in plants, but some animal and protists cells have vacuoles

New cards
62

What are contractile vacuoles?

Found in many freshwater protists, pump excess water out of cells

New cards
63

What are central vacuoles?

Found in many mature plant cells; holds organic compounds and water; store toxins and waste; water creates turgor pressure, helps to physically support plants

New cards
64

What organelles are found in animal and plant cells?

  1. Nucleus (nuclear envelope, nucleolus, chromatin)

  2. Rough ER

  3. Smooth ER

  4. Golgi apparatus

  5. Ribosomes

  6. Microfilaments

  7. Cytoskeleton (microtubules and mitochondrion)

  8. Peroxisome

  9. Plasma membrane

New cards
65

What organelles are found in plant cells but not animal cells?

  1. Central vacuole

  2. Chloroplasts

  3. Cell wall

  4. Plasmodesmata

  5. Glyoxysome

New cards
66

What are the functions of the cytoskeleton?

-supports the cell and maintains its shape

-keeps organelles anchored in place

-cell movement

+interacts with motor proteins

+cytoplasmic movement, streaming -transport of materials throughout cell

New cards
67

What are the three primary fibers to the cytoskeleton?

Intermediate filaments, microtubule, microfilaments

New cards
68

What is the first primary fiber to the cytoskeleton?

Intermediate filaments: tough, woven cables of proteins. Provide structure and strength. Anchors organelles; intermediate in diameter; made of protein subunit: keratin

New cards
69

What is the structure of the first primary fiber to the cytoskeleton?

Fibrous proteins coiled into cables

New cards
70

What is the second primary fiber to the cytoskeleton?

Microtubule: largest cytoskeletal element

-can lengthen and shorten rapidly

-used in cell division; broadest in diameter; made of protein subunit: tubulin (bead-like)

New cards
71

What is the structure of the second primary fiber to the cytoskeleton?

Hollow tubes

New cards
72

What is the third primary fiber to the cytoskeleton?

Microfilament: long, slender filaments. Move the cell or change its shape by shortening and elongating; smallest in diameter; made of protein subunit: actin (bead-like)

New cards
73

What is the structure of the third primary fiber to the cytoskeleton?

Two intertwined strands of actin

New cards
74

Define dynamic instability.

A fiber's ability to switch between growing and shrinking

New cards
75

Which fibers have dynamic instability?

Microtubules and microfilaments

New cards
76

Where are microtubules found?

Cilia, flagella, and centrosomes; microtubules control the beating of cilia and flagella

New cards
77

What are cilia and flagella?

Cellular appendages that help cells move in their environment (locomotion); similar structure-> different functions

New cards
78

What is the structure of microtubules in cilia and flagella?

9 fused pairs on the outside, 2 un-fused microtubules inside

New cards
79

Define flagella.

Long appendages, used to propel the cell through fluid. Allow locomotion; present in prokaryotes and eukaryotes

New cards
80

Define cilia.

Short appendages, used for movement or moving fluid past the cell; present only in eukaryotes

New cards
81

What are motor proteins?

Proteins that use energy to physically walk along microtubule tracks

New cards
82

What are centrosomes?

"Microtubule-organizing center" an organelle that consists of a pair of centrioles made from microtubules

New cards
83

What is the function of centrosomes?

Organize microtubules that are needed for cellular division

New cards
84

Where are microfilaments found?

Microvilli (made from microfilaments), pseudopod, and muscle fibers

New cards
85

What is the structural role of microfilaments for microvilli?

To bear tension, resisting pulling forces within the cell

New cards
86

What is the role microfilaments play in some cells?

Increase the membrane's surface area

New cards
87

How does the pseudopod movement occur?

Through actin polymerization

New cards
88

Muscle fibers are made of...

Actin (microfilament) and myosin (motor protein)

New cards
89

What does myosin do for muscle fibers?

Myosin uses ATP-> closes or elongates the gap between the microfilaments/ muscle fiber (allowing your muscles to contract and body to move)

New cards

Explore top notes

note Note
studied byStudied by 54 people
... ago
5.0(2)
note Note
studied byStudied by 3 people
... ago
5.0(1)
note Note
studied byStudied by 81 people
... ago
5.0(1)
note Note
studied byStudied by 36 people
... ago
4.5(2)
note Note
studied byStudied by 12 people
... ago
5.0(1)
note Note
studied byStudied by 21676 people
... ago
4.7(21)
note Note
studied byStudied by 39 people
... ago
5.0(1)
note Note
studied byStudied by 159 people
... ago
5.0(1)

Explore top flashcards

flashcards Flashcard (53)
studied byStudied by 1 person
... ago
5.0(1)
flashcards Flashcard (43)
studied byStudied by 7 people
... ago
5.0(1)
flashcards Flashcard (28)
studied byStudied by 15 people
... ago
5.0(1)
flashcards Flashcard (42)
studied byStudied by 4 people
... ago
5.0(1)
flashcards Flashcard (71)
studied byStudied by 4 people
... ago
4.0(1)
flashcards Flashcard (76)
studied byStudied by 3 people
... ago
5.0(1)
flashcards Flashcard (21)
studied byStudied by 7 people
... ago
5.0(1)
flashcards Flashcard (36)
studied byStudied by 126 people
... ago
5.0(3)
robot