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Flashcards in Cell Structure Deck (124):
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-bounded unit containing DNA and cytoplasm

cell

4

a group of similar cells that carry out a particular function

tissue

5

structures composed of more than one type of tissue

organ

6

related organs performing a common function

organ system

7

an individual, independent, living entity

organism

8

Cells are small to maintain a large -- ratio in order to function

surface area to volume

9

all prokaryotic cells have a plasma membrane, nucleoid, and cytoplasm containing --

ribosomes

10

outside prokaryotic cells may be a --

cell wall

11

bacteria's cell wall contain --

peptidoglycan

12

prokaryote that photosynthesizes?

cyanobacteria

13

some prokaryotes swim using

flagella

14

what is projected from the surface of prokaryotic cells that is involved in mating

pili

15

eukaryotic cells contain an internal cytoskeleton that maintains -- and moves materials

cell shape

16

plant cell wall is mainly composed of

cellulose

17

largest organelle; contains most of the cell's DNA

nucleus

18

nuclear envelope is made up of two membranes perforated by --

nuclear pores

19

DNA is combined with protein to form --

chromatin

20

when the nucleus is about to divided chromatin condenses and coils tightly forming --

chromosomes

21

each chromosome ("colored body") contains -- which is comprised of many genes

one long molecule of DNA

22

T or F: the nucleus may contain more than one nucleolus

True

23

site of ribosome assembly

nucleolus

24

fluid material within the nuclear envelope

nucleoplasm

25

a network of proteins which maintains shape of nucleus

nuclear lamina

26

all cells synthesize proteins on

ribosomes

27

3 locations of ribosomes in eukaryotes

1. free in cytoplasm
2. attached to ER
3. in energy-producing organelles (mitochondrial matrix, chloroplast stroma)

28

cells which synthesize proteins for export contain large amounts of --

ER

29

site for hydrolysis of glycogen

smooth ER

30

synthesis of steroids

smooth ER

31

makes proteins

rough ER

32

site for addition of short sugar chains to proteins (glycoproteins)

rough ER

33

cis Golgi apparatus lies closer to --

nucleus

34

trans Golgi apparatus lies closer to --

cell surface

35

modifies, packages, and sorts proteins

Golgi apparatus

36

synthesizes some polysaccharides for the cell wall

Golgi apparatus

37

vesicles from the rough ER fuse with the -- region of the Golgi apparatus and secretory vesicles are pinched off the the -- region

cis, trans

38

specific hydrophobic sequence of about 25 amino acids at the beginning of a polypeptide chains directs it into the ER

signal sequence

39

signal sequence is removed by --

an enzyme

40

converts energy from food in to ATP

mitochondria

41

the size of mitochondria is similar to

bacteria

42

the inner membrane of the mitochondria is highly folded forming --

cristae

43

part of the mitochondria that contains ribosomes and DNA

matrix

44

almost all eukaryotes contain mitochondria except those --

living in environments without oxygen

45

more mitochondria are present if cells are --

very active

46

plastids are present in --

plants and some proteins

47

serves for food manufacture or storage

plastids (e.g. chloroplasts carry out photosynthesis)

48

plastids are surrounded by -- membranes

2 unfolded

49

inner membrane of plastids form a stack of flattened disk-like sacs called

thylakoids

50

stacks of thylakoids are called

grana

51

chlorophyll is contained in the

thylakoid membrane

52

fluid within inner membrane of chloroplast

stroma

53

contain hydrolytic digestive enzymes

lysosomes

54

participate in phagocytosis

lysosomes

55

organelle that break downs and stores in plants and animals

peroxisomes

56

organelle that break downs and stores in plants only

glyoxysomes

57

vacuoles are present in plant cells and store -- and provide --

waste, turgor

58

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

cytoskeleton

59

organelle involved in support present in plants, fungi, bacteria, and some protists

cell wall

60

surround animal cells and is composed of protein (collagen, glycoproteins, and proteoglycan)

extracellular matrix

61

components of cytoskeleton

microfilaments, intermediate filaments, and microtubules

62

strands of actin

microfilaments

63

involved in movement during animal division

microfilaments

64

muscle contraction

microfilaments

65

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

intermediate filaments

66

hollow cylinders made of tubulin

microtubules

67

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

microtubules

68

motor proteins like -- and -- use energy from ATP to change their shape and move things

dynein and kinesin

69

All cells are bounded by a

plasma membrane

70

A plasma membrane provides a -- which has the ability to transport certain molecules

permeability barrier

71

The plasma membrane plays a key role in the --

response of cells to external stimuli

72

Plasma membranes are also involved in energy --

transduction

73

Membranes of composed of ---

lipids, proteins, and carbohydrates

74

-- provide physical integrity to membranes

lipids

75

-- perform specific functions for the membranes such as transport

proteins

76

-- serve as recognition sites on the cell surface

carbohydrates

77

phospholipids spontaneously form bilayer sheets in which the -- point inward

hydrophobic tails

78

as temperatures falls, lipid bilayer changes from a -- state to a -- state

fluid, rigid (gel)

79

if the hydrocarbon chains of a bilayer sheet are short or have double bonds then the temperature of the phase transition is --

lower

80

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

cholesterol

81

the nonpolar interior of the lipid bilayer prevents passage of any -- molecules through the bilayer

water-soluble

82

permeability of water-soluble molecules occur because of --

specific protein molecules

83

explains how proteins are incorporated into the lipid bilayer

fluid mosaic model

84

on the outer surface of the plasma membrane carbohydrates are attached to --

proteins or phospholipids

85

-- proteins penetrate into the lipid bilayer

integral

86

most integral proteins are -- proteins that penetrate all the way through the bilayer

transmembrane

87

transmembrane proteins contain an alpha-helix of --- extending across the hydrophobic interior of the membrane

nonpolar amino acids

88

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

peripheral proteins

89

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

lipid-anchored proteins

90

beneath the cytoplasmic surface of the red blood cell -- forms a mesh

spectrin

91

3 main roles of membrane proteins

1. transport proteins
2. receptors for molecular messengers from other cells
3. form junctions between cells

92

most carbohydrates in membranes are bound to proteins forming --

glycoproteins

93

-- form cell identity markers

glycolipids

94

cells recognize and bind to each other via --

surface membrane proteins

95

3 types of cell adhesion

tight junctions, desmosomes, and gap junctions

96

within cells, solutes distribute rapidly by -- due to the short distances involved

diffusion

97

movement is down the concentration gradient

diffusion

98

movement is against the concentration gradient

active transport

99

-- can diffuse across the lipid bilayer

small nonpolar molecules like oxygen and carbon dioxide

100

molecules with -- diffuse more rapidly

higher lipid solubility

101

diffusion of water molecules across a selectively permeable membrane

osmosis

102

water diffuse out of a cell

hypertonic

103

water diffuse into a cell

hypotonic

104

T or F: ions (Na+) being charged can readily cross membranes

false

105

ions pass through -- to cross membranes

aqueous channels created by intrinsic membrane proteins

106

certain molecules (glucose) bind to -- in the membrane and are transported across

carrier proteins

107

facilitated diffusion is -- and may become -- if all the protein carriers are in use

specific, saturated

108

-- active transport requires the direct participation of ATP

primary

109

-- active transport utilizes the energy in an ion gradient established by primary active transport

secondary

110

the sodium-potassium pump is an example of -- active transport

primary

111

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

endocytosis

112

in endocytosis, the -- envelops materials and forms a vesicle inside the cell

plasma membrane

113

large particles are engulfed

phagocytosis

114

small dissolved solutes or fluids enter a cell

pinocytosis

115

a specific membrane receptor binds to a particular macromolecule at sites called coated pits

receptor-mediated endocytosis

116

uptake of cholesterol in association with LDL is an example of -- endocytosis

receptor-mediated

117

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

exocytosis

118

first law of thermodynamics

energy cannot be created or destroyed

119

second law of thermodynamics

during any energy interconversion, some energy is released as heat which adds to the entry of the system

120

the sum of all chemical processes occurring within a cell or organism

metabolism

121

chemical reactions establish --

equilibrium

122

the -- is the ration of the concentration of products and reactants at equilibrium

equilibrium constant

123

a -- indicates that the reaction goes far towards completion

high equilibrium constant

124

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

Gibbs free energy