Chapter 3: Cell Structure and Functions Flashcards
1
Q
basic living unit of all organisms
A
Cell
2
Q
The simplest organisms consist of ____ cells
A
single
3
Q
humans are composed of ___ cells
A
multiple
4
Q
4 Cell Structures
A
- Plasma Membrane
- Nucleus
- Cytoplasm
- Organelles
5
Q
control center of the cell
A
Nucleus
6
Q
specialized structures within the cell that perform specific functions
A
Organelles
7
Q
forms the boundary of the cell through which the cell interacts with its environment
A
Plasma membrane
8
Q
living material surrounding the nucleus where most activities take place
A
Cytoplasm
9
Q
4 Functions of Cell
A
- Cell Metabolism and Energy
- Synthesis of molecules
- Communication
- Reproduction and inheritance
10
Q
outermost component of a cell and serves as the boundary between its inside and outside
A
Cell Membrane
11
Q
Cell membrane is also known as ___
A
plasma membrane
12
Q
Cell membrane encloses the cytoplasm and forms the boundary between: ___ and ____
A
- intracellular
- extracellular
13
Q
Cell membrane’s primary role lies in regulating the ____, including nutrients and waste materials
A
passage of substances
14
Q
Cell membrane’s structure is described by the ___
A
fluid-mosaic model
15
Q
In Phospholipid Structure, phospholipids form a ___
A
double layer of molecules.
16
Q
In the phospholipid, the ___ ___ (water-loving) head face the extracellular and intracellular fluids.
A
polar hydrophilic (water-loving)
head
17
Q
The nonpolar hydrophobic (water-fearing) tail face away from the ___
A
fluid, towards the center of the double layer.
18
Q
Cell membranes are ___ ____, allowing some substances to pass into or out of cells while restricting others.
A
selectively permeable
19
Q
Movement through the cell membrane can be either ___ or___
A
- passive
- active
20
Q
require the cell to expend energy, usually in the form of ATP
A
Active Transport Mechanisms
21
Q
Active Transport Mechanisms includes
A
(1) active transport
(2) secondary active transport
(3) endocytosis
(4) exocytosis
22
Q
do not require the cell to use energy
A
Passive Transport Mechanisms
23
Q
Passive Transport Mechanisms includes
A
(1) diffusion
(2) osmosis
(3) facilitated diffusion
24
Q
process where solutes, such as ions or molecules, move from an area of higher concentration to an area of lower concentration.
A
Diffusion
25
Diffusion generally involves the movement of substances in a solution down a ___ ___
concentration gradient
26
a difference in solute concentration between two points divided by the distance between them.
Concentration Gradient
27
acts as a barrier to most water-soluble substances
phospholipid bilayer
28
2 Cell Membrane Channels
- Leak Channels
- Gated Channels
29
open and close to **limit the movement** of ions across the membrane
Gated Channels
30
**constantly allow** ions to pass through
Leak Channels
31
**diffusion of water** across a selectively permeable membrane, such as the cell membrane, from a region of higher water concentration to one of lower water concentration.
Osmosis
32
force required to **prevent water movement** across a selectively permeable membrane.
Osmotic Pressure
33
pushing force on water due to the **presence of more fluid** in one region than another.
Hydrostatic Pressure
34
A cell may be placed in solutions that are either:
- hypotonic
- isotonic
- hypertonic
35
**equal** solute and water concentration
Isotonic
36
lower solute concentration, higher water concentration
Hypotonic
37
higher solute concentration, lower water concentration
Hypertonic
38
transport of molecules from the region of higher concentration to the region of lower concentration **with the help** of carriers.
Facilitated Diffusion
39
Exhibits the properties of specificity, competition, and saturation.
Carrier-Mediated Transport
40
3 Types of Carrier-Mediated Transport
- Facilitated Diffusion
- Active Transport
- Secondary Active Transport
41
___ ____ does not require ATP for energy
Facilitated Diffusion
42
__ ___ does require ATP for transport.
Active Transport
43
- carrier-mediated process, requiring ATP, that moves substances across the cell membrane **from regions of lower concentration to those of higher concentration** against a concentration gradient.
- can move substances from lower concentration
Active Transport
44
uses the energy provided by a concentration gradient established by the active transport of one substance, such as Na+ to transport other substances.
Secondary Active Transport
45
2 Types of Secondary Active Transport
- Contransport
- Countertransport
46
process that that brings materials **into cell** using vesicles.
Endocytosis
47
3 Types of Endocytosis
- Receptor-mediated endocytosis
- Phagocytosis
- Pinocytosis
48
occurs when a specific substance binds to the **receptor molecule** and is transported into the cell.
Receptor-mediated endocytosis
49
often used for endocytosis when **solid particles** are ingested.
Phagocytosis
50
has much smaller vesicles formed, and they **contain liquid** rather than solid particles.
Pinocytosis
51
membrane-bound sacs
secretory vesicles
52
involves the use of membrane-bound sacs called secretory vesicles that accumulate materials for release **from the cell**.
Exocytosis
53
Examples of exocytosis
secretion of digestive enzymes
54
organelles of the cell:
- nucleus
- ribosomes
- endoplasmic reticulum
- golgi apparatus
- secretory vesicle
- lysosomes
- peroxisomes
- mitochondria
- cytoskeleton
- centriole
55
- large organelle located **near the center** of the cell
- Site of RNA synthesis and ribosomal subunit assembly.
Nucleus
56
The nucleus is bounded by a ___ ___ , which consists of outer and inner membranes with a narrow space between them.
Nuclear Envelope
57
where materials can pass into or out of the nucleus.
Nuclear pores
58
a loosely coiled chromosome that becomes tightly coiled
during cell division.
Chromatin
59
**diffuse bodies** with no surrounding membrane found within the nucleus where subunits of ribosomes are formed.
Nucleoli
60
made of both RNA and protein and are the **site of protein synthesis** in the cell.
Ribosomes
61
**not attached** to any organelle and synthesize proteins used inside the cell.
Free Ribosomes
62
produce integral membrane proteins and proteins that are secreted from the cell.
Ribosomes attached to ER
63
A **series of membranes** forming sacs and tubules that extend from the outer nuclear membrane into the cytoplasm.
Endoplasmic Reticulum
64
attached **with ribosomes**, the sites where proteins are produced.
Rough Endoplasmic Reticulum
65
has **no attached ribosomes** and is a site for lipid synthesis, and cellular detoxification.
Smooth Endoplasmic Reticulum
66
process by which enzymes act on chemicals and drugs to **change their structure and reduce their toxicity**.
Detoxification
67
- consists of closely packed stacks of curved, membrane-bound sacs
- **packing and distribution center** that collects, modifies, packages, and distributes proteins and lipids manufactured by the ER
Golgi Apparatus
68
Golgi Apparatus is also known as
Golgi complex
69
small, **membrane-bound sac** that transports or stores materials within cells.
Secretory vesicles
70
**membrane-bound vesicles** *formed from the Golgi apparatus* and contain a variety of enzymes that function as **intracellular digestive systems**.
Lysosomes
71
membrane-bound vesicles that are **smaller than lysosomes** and contain enzymes that **break down fatty acids and amino acids that produce hydrogen peroxide** (H2O2) as a toxic by-product.
Peroxisomes
72
small organelles responsible for **producing considerable amounts of ATP** by aerobic (with O2) metabolism.
Mitochondria
73
numerous folds of the inner membrane
Cristae
74
The outer membranes have a ____, but the inner membranes have ___ ___
- smooth contour
- numerous folds
75
**internal framework of the cell** that *supports* the cell and *holds* the nucleus and other organelles in place.
Cytoskeleton
76
**hollow structures** formed from protein units called **tubulin** and it is vital for cell shape, division, and building structures like
cilia.
Microtubules
77
**small fibrils** formed from actin protein subunits that structurally support the cytoplasm, determining cell shape.
Microfilaments
78
fibrils formed from protein subunits that are **smaller in diameter than microtubules** but **larger in diameter than microfilaments** and they provide mechanical support/ strength to the cell.
Intermediate filaments
79
a specialized area of cytoplasm close to the nucleus **where microtubule formation occurs** and **contains two centrioles** that facilitate the movement of chromosomes during cell division.
Centrosome
80
cylindrical structures composed of microtubules that **project from the surface of cells** and are responsible for the movement of materials over the top of cells, such as mucus.
Cilia
81
have a structure similar to that of cilia but are **much longer**, and they usually occur only one per cell.
Flagella
82
specialized extensions of the cell membrane that are **supported by microfilaments** and **increase the surface area** of the cell but don't actively move like cilia and flagella do.
Microvilli
83
"to carry out vital functions and necessary metabolic processes essential for the proper functioning of the cell and/or organism."
Cell Activity
84
determined by the type of proteins produced
cell characteristics
85
the cells that make up the human body are formed through _____
cell division and cell differentiation
86
____ contains the information that directs protein synthesis, this process is called __ ___
- DNA
- gene expression
87
a **sequence of nucleotides** that provides a chemical set of instructions for making a specific protein
gene
88
Two Steps of Gene Expression
- Transcription
- Translation
89
**Takes place in the nucleus** of the cells and DNA determines the structure of mRNA through it
Transcriptions
90
Organic Bases of DNA
- Thymine
- Adenine
- Guanine
- Cytosine
91
mRNA contains:
- Uracil
- Adenine
- Cytosine
- Guanine
92
synthesis of proteins based on the information in the mRNA and **occurs in the cell cytoplasm** after mRNA has exited the nucleus through the nuclear pores to the ribosomes.
Translation
93
Two Major Phases of Cell Cycle
- Interphase
- Mitosis
94
Each human cells, except sex cells, contains __ chromosomes.
46 chromosomes
95
involves **formation of 2 daughter cells** from a single parent cell.
Mitosis
96
Mitosis is divided into 4 Phases:
- Prophase
- Metaphase
- Anaphase
- Telophase
97
**Chromatin condenses** to form visible chromosomes.
Prophase
98
Chromosomes **align near the center** of the cells
Metaphase
99
Chromatids **separate** at the beginning of ___
Anaphase
100
The chromosomes begin to **unravel and resemble the genetic material during interphase**
Telophase
101
Two Types of Tumor
- Benign
- Malignant
102
Less dangerous type of tumor which they are **not inclined to spread** but still increase in size.
Benign Tumor
103
**Can be spread** by local growth and expansion or by metastasis
Malignant Tumor
104
refers to **malignant and lack the normal growth control** that is exhibited by most adult tissue
Cancer
105
process by which **cells develop with specialized structures and functions**
Differentiation
106
- normal process by which **cell numbers** within various tissues **are adjusted and controlled**
- regulated by specific genes
Apoptosis
