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Flashcards in Chapter 4 Deck (195):
1

cluster of atoms held together by chemical bonds

molecule

2

structure within a cell that performs a specific function

organelle

3

simplest entity that has all the properties of life; a membrane-bound unit containing DNA and cytoplasm

cell

4

structures composed of more than one tissue type

organ

5

related organs performing a common function

organ system

6

an individual, independent, living entity

organism

7

form boundaries on surfaces (outermost layer of skin, line airway and stomach), control what goes in and out, held by tight junction

epithelial tissue

8

cells imbedded in a matrix (ex. blood: RBC surrounded by a liquid matrix called plasma & bone which has a calcified matrix collagen fibers & adipose tissue)

connective tissue

9

skeletal, smooth (blood vessels, GI tract), cardiac

smooth tissue

10

neurons conduct electrical signals

nervous

11

chemical pathway from simple to complex

anabolism

12

chemical pathway from complex to simple

catabolism

13

Living things....

cellular organization, sensitivity (respond to stimuli), growth, reproduce, homeostasis

14

Cell theory

1) all organisms are composed of cells 2) the cell is the basic building block of life = chemical reactions within 3) all cells come from preexisting cells

15

Why are cells small?

need high/reasonable surface-to-volume ratio and big cell = diffusion distance increases = not efficient

16

two atoms SHARE one, two, three electron pairs --> stable bond

covalent bonds

17

water molecule is formed by ___ bonds between one oxygen atom and two hydrogen atoms

covalent

18

oppositely charged ions attract each other forming an ___ bond

ionic

19

unequal attraction of electrons by the atoms that share them in a covalent bond

polar molecule

20

the attraction of the positive (hydrogen) end of the polar molecule to the negative end of another polar molecule is called

hydrogen bond

21

hydrogen bonds may be weak but can be present in ____ and influence the shape of molecules (DNA double helix is held together by H bonds)

very large numbers

22

water forces the hydrophobic groups together and this is why non polar groups tend to localize ____ of most soluble proteins

within the interior

23

lacks a nucleus; DNA coiled into a nucleoid is in direct contact with the cytoplasm (some have more than one nucleoid)

prokaryotic cells

24

contain a large, membrane bounded nucleus; has organelles

eukaryotic cells

25

All prokaryotic cells have a plasma membrane, nucleoid, and cytoplasm containing ____

ribosomes

26

Prokaryotic: located outside plasma membrane may be a ___

cell wall containing peptidoglycan

27

plasma membrane --> cell wall --> outer membrane --> ___

capsule

28

In bacteria the chlorophyll (no chloroplast) is located in

the infoldings of the plasma membrane

29

some prokaryotes swim using

flagella

30

___ which projects from the surface of some bacteria is involved in mating

pili

31

prokaryote flagellum is made up of

flagellin

32

Eukaryotes contain an internal cytoskeleton which

maintains cell shape and moves materials

33

rigid cell wall of cellulose and large central vacuole

plants

34

eukaryotes's cytoskeletal protein is made up of

myosin and actin

35

ER closest to nucleus

rough (ribosomes)

36

mature RBC

blood cells originate from blood bone marrow; last bout 120 days then broken down in liver
no nucleus cuz going to lose genetic material anyways

37

DNA is contained in

mostly nucleus + mitochondria and chloroplast

38

DNA + protein -->

chromatin

39

when nucleus is about to divide the chromatin ___ forming chromosomes

condenses and coils tightly

40

each __ ("colored body") contains one long molecules of DNA comprising many genes

chromosomes

41

the nucleus contains (one or more) nucleolus the site of

ribosome assembly

42

fluid material within the nuclear envelope

nucleoplasm

43

viruses are made up of __, surrounded by ____

nucleic acid, protein sheath (sometimes lipid envelope)

44

viruses are not alive because

lack cell membranes, nucleus, and organelles; cannot reproduce on their own; no metabolism

45

X formation is ___ to division

prior

46

mitotic spindle is attached to each ____ and pulls them apart to the poles

sister chromatid

47

all cells synthesize proteins on __

ribosomes

48

Where are ribosomes located in eukaryotes?

free in cytoplasm, attached to rough ER, in energy producing organelles (mitochondrial matrix, chloroplast stroma)

49

ribosomes consist of a type of ___ together with protein, comprising a large and small subunit which associate during protein synthesis

RNA

50

____ makes the peptide bond

ribozyme

51

A series of interrelated membranes and compartments in the eukaryotic cells

Endomembrane system = ER + Golgi

52

extensive system of folded membranes forming sacs and tubes

ER

53

cells which synthesize proteins for export contain large amounts of ____

ER

54

lack ribosomes; site for hydrolysis of glycogen; steroid synthesis

smooth ER

55

contains attached ribosomes; makes proteins for export; site for addition of short sugar chains to proteins glycoproteins

rough ER

56

insulin is made and stored in ___

pancreatic beta cells (right below stomach)

57

enclosed spaces

lumen

58

series of flattened membranous sacs that modifies, packages, and sorts proteins

Golgi apparatus

59

synthesizes some polysaccharids for the cell wall

Golgi apparatus

60

vesicles from the rough Er fus with the ___ region of the Golgi (near nucleus) and secretory vesicles are pinched off the the ___ region (close to cell surface)

cis, trans

61

powerhouse of cell

mitochondria

62

food is converted into ATP =

energy currency of cell

63

mitochondria are small/big

small (bacteria size)

64

inner membrane of mitochondria

cristae

65

mitochondrial matrix contains

ribosomes and DNA

66

almost all eukaryotes contain mitochondria except whose living

without oxygen

67

more mitochondria are present if cells are ___ like in heart muscle

very active

68

serves for food manufacture or storage in plants and some protists (ex. chloroplast)

plastids

69

plastids are surrounded by

two unfolded membranes

70

inner membrane of chloroplast forms a stack of flattened disk-like sacs called

thylakoids

71

stacks of thylakoids are called

grana

72

chlorophyll is contained in

the thylakoid membrane

73

___ (fluid) within inner membrane of chlorplast contains suspended grana, ribosomes, and DNA

stroma

74

contains hydrolytic digestive enzymes; participate in phagocytosis

lysosomes

75

What is the pH of lysosomes

5

76

peroxisomes are found in

plants and animals

77

glyoxysomes are found in ___, it stores ___ which is converted in carbs when plant is about to germinate

plant seeds, lipids

78

peroxisomes are important in liver and kidney to

detoxify

79

Tay Sach's disease

defect in lysosomes

80

lysosomes carry out autophagy which is

self-breakdown

81

T or F: plants have lysosomes

false

82

vacuoles are present in ___

plant cells; store waste products and provide turgor

83

maintains cell shape, facilitates cell movement, and certain fibers act as tracks for "motor proteins"

cytoskeleton

84

cell wall are present in __, ___, and some __

plants, fungi, protists (and bacteria)

85

surrounds animal cells and is composed of proteins (e.g. collagen, glycoproteins, and proteoglycan)

extracellular matrix

86

division of the nucleus

mitosis

87

division of cytoplasm

cytokinesis - microfilaments form a noose around the middle of the cell it adds or subtract to change length of actin

88

strands of actin, involved in movement during animal cell division and muscle contraction

microfilaments

89

tough, fibrous protein molecules twisted into rope-like structures, which stabilize cell structure

intermediate filaments

90

hollow cylinders made of tubulin

microtubules

91

involved in structure and function of cilia and flagella, centrioles, and movement of cellular organelles

microtubules

92

motor proteins such as __ use energy from ATP to change their shape and move things

dynein and kinesin

93

cilia are formed of

microtubules

94

structure of cilia

9 pairs of microtubules + 2 in the middle

95

animals don't have cell wall but may have

extracellular matrix

96

vacuoles are __ in animal cells

absent or small

97

some animal cell have flagella it's absent in plants except for

sperm in a few species

98

centrioles ___ in plants

are absent

99

all cells are bounded by a __

plasma membrane

100

plasma membrane provides __ which has the ability to transport certain molecules

permeability barrier

101

plasma membrane plays a key role in response of cells to __

external stimuli

102

membranes are involved in energy __

transduction

103

biological membranes are composed of

lipids, proteins, and carbohydrates

104

provide physical integrity of plasma membranes

lipids

105

perform specific function (e.g. transport, receptors) for plasma membrane

proteins

106

serve as recognition sites on the cell surface

carbohydrates

107

the basic foundation of the plasma membrane

lipid bilayer

108

phospholipids ___ form bilayer sheets in which the ___ tails point inward

spontaneously, hydrophobic

109

fluidity of a bilayer depends on __ and ___

composition and temperature

110

important component of plasma membrane of animal cells orients in bilayer with polar head group close to polar head group of phospholipid

cholesterol

111

unsaturated: C=C puts a kink in a chain so it does not pack well together in membrane -->

harder to freeze

112

on the outer surface of the plasma membrane, __ are attached to proteins or phospholipids

carbohydrates

113

protein that penetrates into the lipid bilayer

integral

114

most integral proteins are __, contain an alpha-helix of non polar amino acids extending across the hydrophobic interior of the membrane

transmembrane

115

located outside of the lipid bilayer on the cytoplasmic surface attached by non covalent bonds to the polar head groups of the lipid bilayer or to the integral membrane proteins

peripheral proteins

116

covalently attached to a phospholipid or fatty acid embedded in the bilayer

lipi-anchored proteins

117

__ provides much info we know about membrane structure

RBC

118

beneath the cytoplasmic surface of the RBC, ___ forms a mesh

spectrin

119

role of membrane proteins

transport, receptors, form junctions between cells

120

cells can recognize and bind to each other via ___

surface membrane proteins

121

stick together by same membrane proteins

homotypic binding

122

stick together by different membrane proteins

heterotypic binding

123

cell junction stitched all the way around

tight junction

124

"spot welds" don't go all the way around but more concerned with structural integrity

desmosomes

125

protein pore or channel between two adjacent cells

gap junctions

126

connexin protein makes a channel called

connexon

127

gap junctions are important in __

the heart, facilitates the spread of an action potential

128

meditate the attachment of animal cells to extracellular matrix

inegrin

129

passive, non mediated movement down concentration gradient most simple

diffusion

130

when molecules become uniformly distributed a state of __ exists

equilibrium

131

diffusion of water molecules across a selectively permeable membrane

osmosis

132

Ions such as Na+ and other charges do not readily cross membranes but can pass through water filled pores created by ____

intrinsic membrane proteins (channels)

133

certain molecules (eg glucose) bind to carrier proteins in the membrane and are transported across

facilitated diffusion

134

facilitated diffusion may become ___ if all the protein carriers are in use

saturated

135

transport across a membrane by a carrier-mediated process against concentration gradient

active transport

136

requires direct participation of ATP

primary active transport

137

does not use ATP directly but rather the energy in an ion gradient established by primary active transport

secondary active transport

138

transports macromolecules, large particles, and small cells into eukaryotic cells

endocytosis

139

during endocytosis, the plasma membrane envelops materials and forms ___ inside cells

vesicle

140

large particles or cells are engulfed

phagocytosis

141

small dissolved solutes or fluids enter

pintocytosis

142

a specific membrane receptor binds to a particular macromolecule at sties called coated pits (e.g. uptake of cholesterol in association with LDL)

receptro-mediated

143

material in vesicles are secreted from the cell when vesicles fuse with the plasma membrane

exocytosis

144

work associate energy

kinetic

145

stored energy

potential

146

energy from the sun flows in the biological world and stored as ___ in the chemical bonds of sugar molecules formed by photosynthesis

potential energy

147

first law of thermodynamics

energy cannot be created or destroyed

148

second law of thermodynamics

during any energy conversion, some energy is released as heat which adds to entropy (increasing disorder) of the system

149

the sum of all chemical reactions within a cell or organism

metabolism

150

product of one reaction becomes the reactant in the next reaction

metabolic pathway

151

chemical reaction establish

equilibrium

152

what is the ratio of the concentration of products and reactants at equilibrium

equilibrium constant Keq

153

high Keq -->

reaction goes far towards completion

154

the breaking of chemical bonds in the course of chemical reactions produces changes in ___

Gibbs free energy

155

Give an example of an anabolic reaction

glucose + fructose + (energy) --> sucrose

156

Give an example of a catabolic reaction

sucrose is hydrolyzed --> energy is released

157

in a biological system, the released energy may be __ in new chemical bonds or used as __

recaptured, kinetic energy

158

the energy released by the breakdown of glucose is used to drive the synthesis of ___

triglycerides

159

Total energy

enthalpy, H

160

G =

H-TS

161

If delta G < 0

free energy is released, exergonic

162

If delta G > 0

free energy is required, endergonic

163

the further toward completion the point of equilibrium lies, the ___ free energy is released

more

164

The proteins of tight junctions form a ___ barring the movement of dissolved materials through the space between epithelial cells

quilted seal

165

__ link adjacent cells tightly but permit materials to move around them in the intercellular space

Desmosomes

166

Gap junctions let adjacent cells ___

communicate

167

__ and __ are abundant in epithelial cells

tight junctions and desmosomes

168

__ are found in some muscle tissue and nerve tissue win which __ between cells is important

gap junctions, rapid communication

169

True or False: All three junctions are not necessarily seen at the same time in actual cells

true

170

A __ solution has a higher solute concentration than the other solution

hypertonic

171

__ solutions have equal solute concentrations

isotonic

172

A __ solution has a lower solute concentration that the other solution

hypotonic

173

How fast a substance diffuses depends on

diameter or molecules or ions, temperature of solution, concentration gradient

174

__ keeps plants upright and is the driving force for the enlargement of plant cells

turgor pressure

175

sometimes a stimulus is the binding of a chemical signal __ to open gated channel

ligand

176

Protein __ coats the cytoplasmic side of the plasma membrane at the coated pit

clathrin

177

the endocytosed contents are surrounded by

a clathrin-coated vesicle

178

__ is the method by which cholesterol is taken up by most mammalian cells

receptor-mediated endocytosis

179

When a cell need cholesterol, it produces specific __ which are inserted into the plasma membrane in clathrin coated pits

LDL receptors

180

A newly formed polypeptide may contain a __ which is a short stretch of amino acids that indicates where in the cell the polypeptide belongs

signal sequence

181

A signal sequence binds to a specific __ at the surface of the organelle

receptor protein

182

in the absence of a signal sequence, the protein will __ in the same cellular compartment where it was synthesized

remain

183

protein synthesis always begins on free ribosomes and have default location for a protein is the __

cytosol

184

Once the protein has bound to a specific receptor protein, the receptor forms a __ in the membrane and the protein enters the organelle

channel

185

a specific hydrophobic sequence of about __ at the beginning of a polypeptide chain directs it into the ER

25 amino acids

186

Nucleic acids inside protocells could replicate using the ___ from ___

nucleotides from outside

187

found in cytoplasm (on ribosome), binding of mRNA and tRNA and protein synthesis

rRNA

188

found in cytoplasm, carrier of gene sequence

mRNA

189

found in cytoplasm, adapter between mRNA and protein sequences

tRNA

190

in plants, SER

metabolizes carbohydrates

191

membranes of the nucleus, ER, and Golgi form a

network connected by vesicles

192

Blood Cholesterol Levels

200 mg/dL, 200-239, 240+

193

LDL cholesterol levels

130 mg/dL, 130-159, 160+

194

Blood cholesterol made in

liver

195

cholesterol is coated with a layer of protein to make __ which can move in blood

lipoprotein