Chapter 3: Cells Flashcards
1
Q
Structure dictates _____
A
function
2
Q
What is the meaning of the word “eukaryote”?
A
“true nut”
3
Q
What do prokaryotic cells lack?
A
Nucleus
4
Q
What type of cells are human cells?
A
Eukaryotes
5
Q
Cytoplasm
A
All liquid within the cell that’s not in the nucleus
6
Q
What is present inside organelles?
A
Cytoplasm
7
Q
Cytosol
A
The liquid portion inside the cell that’s NOT inside any organelles
8
Q
What are the functions of a membrane?
A
-controls passage of substances
-detects chemical messengers
-links adjacent cells
-anchors cells to extracellular matrix
9
Q
What is the composition of a membrane?
A
Phospholipid bilayer
10
Q
What are the three notable properties of a membrane?
A
-nonpolar
-fluid mosaic
-selectively permeable
11
Q
Integral proteins
A
Embeds in a membrane
12
Q
Transmembrane proteins
A
integral protein that goes all the way through a membrane
13
Q
What is the function of a transmembrane protein?
A
Creates ion channels
14
Q
Peripheral proteins
A
Not embedded withing the structure of the membrane
15
Q
What is the function of a peripheral protein?
A
Helps with cellular communication
16
Q
What components are imbedded in the phospholipid bilayer?
A
-glycoproteins for cell recognition
-cholesterol hold cell layer together
17
Q
Junctions
A
Where cells come together
18
Q
Integrins
A
Transmembrane proteins that connect cells
19
Q
Desmosome
A
region between two adjacent cells held together by proteins
20
Q
Cadherins
A
The proteins extending into extracellular space
21
Q
Where are cadherins found?
A
Epithelial tissue
22
Q
Tight junction
A
When two cells come together tightly; creates a tissue barrier
23
Q
Gap junction
A
two cells connected by a protein; allows for quick information transfer
24
Q
Nucleus
A
Stores and protects genetic information (DNA)
25
Nuclear envelope
Tightly controlled phospholipid bilayers
26
Nuclear pores
proteins that allow certain substances across two membranes
27
What specific molecule moves through nuclear pores?
RNA
28
Nucleolus
Synthesizes ribosomes
29
Ribosomes
Synthesizes proteins
30
What does RNA bind with to carry out reactions?
Ribosomes
31
ER
endoplasmic reticulum
32
Rough ER
involved in protein synthesis due to heavy amount of ribosomes
33
Smooth ER
Synthesizes lipids, stores calcium
34
Golgi apparatus
Postal service of the cell; protein modification
35
Secretory vesicle
-Golgi
-Sends things outside of the cell
36
Mitochondria
Produces ATP
37
Hierarchy of mitochondrial layers
-outer membrane
-intermembrane space
-inner membrane
-matrix
38
What are the folds in the inner membrane of the mitochondria called?
Cristae
39
Lysosomes
contains digestive enzymes; breaks down things the cell eats
40
Peroxisomes
-breaks down hydrogen peroxide
-lipid metabolism, which generates more ATP
41
Cytoskeleton
provides structure and support for the cell
42
Actin filaments
-composition
-addition?
-function
-G-actin (golbular)
-can easily be broken down or added to
-helps cells move
43
Intermediate filaments
-composition
-addition?
-function
-composed of desmin
-cannot be easily broken down
-provides structural support
44
Microtubules
-compositon
-addition?
-function
-composed of tubulin
-can easliy by broken down/added to
-movement within the cell
45
Centrioles
guide mitosis
46
Central Dogma
DNA --transcription--> RNA --translation--> Protein
47
Transcription Factors
Control the transcription of central dogma
(DNA --> RNA)
48
Protein Degradation
Proteins break down/become denatured over time
49
Ubiquitin
Special protein that tags damaged proteins and brings them to a proteasome
50
Proteasome
Special protein that unfolds the damaged protein into small peptides
(garbage disposal of cell)
51
Ligand
Any molecule that binds to a protein
52
Binding Site
The region of a protein that a ligand binds to
53
What happens to a protein when it is bound to a ligand?
It's conformation changes
54
Chemical Specificity
Whether or not a binding site CAN bind to a certain ligand or not
55
Chemical Affinity
How strongly a ligand binds to a protein
56
Specificity is dependent on _____, while affinity is dependent on _____.
Shape; charge
57
Saturation
How many of the total binding sites are occupied
58
What occurs to a protein when it is fully saturated?
The reaction the protein is involved in occurs as fast as possible
59
Allosteric modulation
When one binding site at a protein is bound to a ligand, which changes the shape of another binding site
60
Functional Site
Carries out the protein's physiological function
61
Regulatory Site
The other site on a protein that, when bound to a moldulator molecule (ligand), changes the shape and function of the functional site
62
Modulator molecule
Binds to the regulatory site and changes the shape and function of the regulatory site
63
Covalent modulation
Actual bonds shared between protein and ligand
64
Phosphorylation
Covalent modulation in which a phosphate group is added
65
Kinase
Mediates protein phosphorylation
66
Phosphatase
Removes a phosphate
67
Catabolism
The breaking down of organic molecules
68
Anabolism
The synthesis of organic molecules
69
Chemical bonds
Shared electrons
70
Forming a bond requires __________
An input of energy
71
What are the four determinants of reaction rates?
-concentration
-activation energy
-temperature
-catalyst
72
Law of Mass Action
the direction of a chemical reaction is determined by the concentrations of reactants and products
(based on reversible reactions)
73
Enzymes
Protein Catalyst
74
Substrate
Ligand
75
Lock and Key model
Substrates fit perfectly into the enzyme
76
Induced fit model
Substrates change the shape of the active site in order to fit
77
What is the main function of an enzyme?
Changes the rate of chemical reaction; does not undergo a reaction
78
Cofactors/coenzymes
Metal Ions or vitamin derivatives that participate in the reaction as a substrate
79
Common cofactors
NAD+, FAD
80
What is the function of a coenzyme?
Helps carry molecules from one substrate to another; vital in the occurrence of a reaction
81
What three factors are enzyme-mediated reactions regulated by?
-substrate concentration
-enzyme concentration
-enzyme activity
82
Metabolic pathways
Basis of cellular metabolism; breaks down molecules to form necessary cellular products
83
Which form of feedback do metabolic pathways often use?
Negative feedback loop
84
Allosteric inhibitor
Something that binds to the enzyme other than the active site and turns off the pathway
85
Examples of metabolic pathways
-hydrolysis of ATP
-glycolysis
-Krebs cycle
-oxidative phosporylation
86
Hydrolysis of ATP
Form of metabolism where the terminal phosphate group is removed from ATP and energy is released
87
Glycolosis
-takes place in the cytosol of the cell
-end product: pyruvate
-per glucose molecule: 2 NADH, 2 ATP, 2 pyruvate
88
Krebs Cycle
Fate of pyruvate if oxygen is present
89
Where does the Krebs Cycle occur?
Mitochondrial Matrix
90
The Krebs Cycle results in what product?
The most amount of reduced coenzyme (acetyl-Co A)
91
Lactic Acid pathway
-fate of pyruvate if no oxygen is present
-repeats glycolysis quickly
92
Reduced coenzymes
-NADH
-FADH2
93
Substrate level phosphorylation
GTP
(high energy molecule made of guanine)
94
For every TWO molecules of glucose that enter the Krebs cycle:
-6 NADH
-2 FADH2
-4 CO2 (waste)
-2 ATP/ GTP
95
For every ONE molecule of glucose entering glycolysis:
-2 NADH
-2 ATP
-2 pyruvate
96
Chemiosmosis
Moves ions across a semipermeable membrane from high to low concentration
97
Oxidative phosphorylation
Uses H+ ions and an electron transport chain to pump electrons through a protein complex to synthesize ATP
98
What is the final electron acceptor in the electron transport chain of oxidative phosphorylation?
Oxygen
99
What is the waste product of oxidative phosphoprylation?
Metabolic water
100
Three main metabolic processes and their functions
-Glycolysis: generates pyruvate
-Krebs cycle: generates lots of reduced coenzyme
-Oxidative phosphorylation: releases ATP
