An Introduction to the Structure of Cells Flashcards

Question

Types of Eukaryotes

Answer 1

Protists Fungi Plants Animals

Answer 2

Compartmentalised Plasma membrane Cytoplasm Organelles Nuclear envelope Nucleus

Answer 3

Plants Fungi

Answer 4

Provides mechanical support Protects against infection

Answer 5

True nucleus

Answer 6

Before nucleus

Answer 7

Composed of fibres of cellulose embedded in polysaccharides and proteins Interconnected by plasmadesmata

Answer 8

Physical passageway in cell wall Allows communication and movement of molecules between cells that the cell wall would stop

Answer 9

Large membrane bound sac in plant cells Stores proteins, pigments and waste Presses against cell wall giving tugor pressure

Answer 10

Found in some protist cells Stores water coming in by osmosis then expels the water Stops the cell bursting from excess water

Answer 11

Central (plant) Contractile (protists) Phagocytic Food

Answer 12

Region of eukaryotic cells that is inside the plasma membrane and outside the organeles

Answer 13

Cytosol + Organelles

Answer 14

Metabolism Catabalism

Answer 15

Utilisation of energy for synthesis of materials

Answer 16

Breakdown of materials to utilize energy and generate building blocks for construction macromolecules Each step catalysed by an enzyme

Answer 17

Contains DNA Spherical Surrounded by nuclear envelope

Answer 18

Inside nucleus Site of intense ribosomal RNA synthesis

Answer 19

Double membrane Has nuclear pores to allow passage of substance Interior filled with fluid containing chromosomes

Answer 20

Chromosomes

Answer 21

Distinct Non-overlapping Where each chromosome is located within the cell nucleus of eurkaryotic cells

Answer 22

Unit of genetic material Composed of DNA and proteins

Answer 23

Central histone Spacer histone

Answer 24

Formed by DNA coiled around clusters of histones Looks like beads on a string

Answer 25

Nucleoplasm

Answer 26

Made of intermediate filaments Lines the inner nuclear membrane Attaches to chromatins which helps maintain nuclear shape and keep chromosomes in their territories

Answer 27

Site of protein synthesis

Answer 28

Ribosomal Ribonuceic acid (rRNA) bound with several dozen types of protein 2 subunits, 1 large and 1 small

Answer 29

Only when attached to messenger RNA (mRNA) mRNA contains the code required to make the protein

Answer 30

Make proteins that function in the cytoplasm

Answer 31

Ribosomes on the rough endoplasmic reticulum

Answer 32

Rough endoplasmic reticulum

Answer 33

They share the same genome But the proteome is different

Answer 34

Complete genetic composition of a species

Answer 35

The proteins that a cell can make

Answer 36

Different proteins Different proportions of the same protein Slightly different variants of proteins Modifications of proteins

Answer 37

Smooth and rough Folded inner membranes (cisternae) give it an enormous surface area

Answer 38

Site of protein synthesis Covered with ribosomes Proteins may be chemically modified there

Answer 39

Glycosylated to become glycoproteins Have "address label" signal sequences added

Answer 40

A protein that has carbohydrate attached to it

Answer 41

The attachment of carbohydrate to a protein or lipid Produces a glycoprotein or glycolipid

Answer 42

Exported Sent to the lysosomes or vacuoles Become part of the plasma membrane

Answer 43

The signal sequences attached

Answer 44

Free ribosomes produced in cytosol If mRNA contains an ER signal sequence the ribosome attaches to the ER ER signal sequence recognised by signal recognition particle (SRP) SRP docks ribosome over channel protein in ER Channel protein opens Translation resumes and the growing polypeptide is threaded through the channel The ER signal sequence is removed Protein either released into ER lumen or embeds in ER membrane

Answer 45

Has ribsomes attached

Answer 46

Occurs during protein synthesis First step of the sorting process happens during translation Ribosome attaches to ER if mRNA contains an RE signal sequence

Answer 47

Diverse functions Few ribsosomes

Answer 48

Chemically modifies small molecules like drugs and alcohol Hydrolyses glycogen Synthesises and modifies lipids and steroids Accumulates calcium ions

Answer 49

Cargo (maybe protein molecules) binds to receptors on ER membrane Cargo loaded into forming vesicle Vesicle pinches off the membrane and is released Coat proteins are shed V-snares bind to T-snares on target membrane Vesicle fuses with target membrane to deliver cargo

Answer 50

Facilitate the formation of vesicles in transporting cargo from the ER

Answer 51

Receives proteins from ER and modifies them Concentrates, packages and sorts proteins Sends them on to other destinations in secretory vesicles Synthesises polysaccharides in plant cells

Answer 52

Simple - 1 or few Animal - About 20 Plant - 100s

Answer 53

Chaperone keeps protein unfolded Sorting signal sequence binds to receptor on mitochonrion membrane Chaperone released, protein transferred into channel New chaperones bind to protein as it enters matrix Sorting signal sequence cleaved off Protein completely enters matrix Chaperone released and protein folds into final 3D structure

Answer 54

To prevent the protein from folding early and not fitting through the protein channels

Answer 55

Animal cells

Answer 56

Maybe dozens per cell

Answer 57

By budding from the endomembrane system

Answer 58

Digestion of molecules taken up from outside the cell by endocytosis Recycling cellular molecules

Answer 59

pH4.8 Maintained by H+ ion pumps

Answer 60

Has a very acidic pH Because of this the enzymes inside work optimally at a pH of around 4.8 The pH of the cytosol is 7 (neutral) Therefor the enzymes would not be able to work very effectively outside the lysosme

Answer 61

Engulfs the thing it digests

Answer 62

Used by lysosomes Hydrolitic enzymes Use a molecule of water to break a covalent bond Work at an acidic pH

Answer 63

Oxidative phosphorylation On the inner membrane

Answer 64

Liver Heart Muscle

Answer 65

Much folded inner membrane to form cristae Gives it a large surface area

Answer 66

Converts energy stored in organic molecules into ATP Synthesis, modification and breakdown of other molecules like hormones

Answer 67

Enzymes Ribosomes

Answer 68

Outer - Smooth and permeable Inner - Much folded, selectively permeable, embedded with protein complexs

Answer 69

Chloroplasts

Answer 70

Have their own DNA and can stimulate it's own replication But depend on other parts of the cell for internal components

Answer 71

Mitochondria Chloroplasts

Answer 72

Hundreds of granum surrounded by stroma

Answer 73

Inside chloroplasts Stacked Membranous Contains several compartments called thylakoids

Answer 74

Fluid inside chloroplasts Contains enzymes, ribosomes and DNA

Answer 75

Light capturing pigments on surface Often connected to make a complex membranous system

Answer 76

Hundreds per cell, especially in the liver Collect toxic hydrogen peroxide and breaks it down to harmless water and oxygen using catalase

Answer 77

Enzyme Used by peroxides to break hydrogen peroxide into water and oxygen

Answer 78

In plant, animal, fungi and simple eukaryotic cells Formed by budding from the ER Grow by incorporating proteins and lipids and then divide

Answer 79

Describes a symbiotic relationship where the smaller species lives inside the larger one

Answer 80

They have their own DNA

Answer 81

Descended from bacteria that existed inside eukaryotic cells in endosybiotic relationship Over time (about 2 billion years) adapted to living in the cell and changed to mitochondria we see today

Answer 82

Eukaryotic cell able to synthesise greater amounts of ATP Purple cell may have benefited from stable environment and nutrients provided by cytosol (we don't really know)

Answer 83

Purple bacterium

Answer 84

Double layered outer membrane Same size as prokaryotes Some prokaryotes have folded membranes resembling cristae Prokaryotes have similar sized and structured ribosomes Have circular DNA molecules like prokaryotes Share similar genes to prokayrotes Divide by binary fission Have own DNA

Answer 85

Inner membrane from original engulfed cell Outer membrane from invaginated plasma membrane of host cell

Answer 86

Have their own that codes for proteins needed for some functions Some DNA moved to nucleus during evolution to help cell control mitochondria

Answer 87

Intermediate filament Microtubule Actin filament (microfilament)

Answer 88

Network of 3 different types of protein filaments Found primarily in the cytosol and in the nucleus along the inner nuclear membrane

Answer 89

Two protein strands made of actin subunits twirled together Formed spontaneously Have + and - ends

Answer 90

The positive (+) end

Answer 91

Lie near plasma membrane aSupports and allows quick changes in cell shape

Answer 92

Cell movement Crawling Pinching in cell division Formation of cellular extensions Supporting microvilli in intestine

Answer 93

Most durable cytoskelatal element Stable, don't break down Like cables on suspension bridge Intermediate in size between actin and microtubules

Answer 94

Stop cells stretching out of shape Bears tension

Answer 95

Tough, fibrous proteins twined in overlapping arrangement

Answer 96

Hollow cylinders Ring of 13 protofilaments + end faces away from nucleation centre, - towards Rapidly polymerise and depolymerise to rapidly change in length

Answer 97

Rigid framework in cells Involved in organising cell wall (plant cells) Distributes chromosomes during cell division (mitotic spindle) Move materials within the cell Anchor organelles in place

Answer 98

Have a + and -end Hollow cylinders Ring of 13 protofilaments Globular proteins made of dimers of alpah- and beta- tubulin polymerise to form microtubule

Answer 99

From centrosome or microtubule organising centre Radiates out

Answer 100

Consists of a head, tail and hinge ATP hydrolysed at head Hinge bends from hydrolysis of ATP Tail region attached to other components

Answer 101

At leading edge actin filaments polymerise pulling it forwards Microtubules polymerise to stabilise this region Myosin motors along actin filaments contract pulling cell towards newly extended front edge

Answer 102

Receptors on cell surface respond to chemical signals

Answer 103

Flagella or cilia

Answer 104

No Very different

Answer 105

Same but cilia shorter and more numerous Main part made up of axoneme Anchored to basal body that sits just within the cell boundry Linker protein nexin joins pairs of mircotubules

Answer 106

2 central microtubules Surrounded by 9 microtubule doublets Each of 9 pairs joined by the linker protein nexin

Answer 107

Sits just within cell boundry Has 9 triplet microtubules

Answer 108

Dynein is activated to walk towards the - end of microtubules Linking proteins hold dynein and microtubules in place This tops dynein just walking up microtubules Instead causes it to exert a force that bends the microtubules This causes movement to start at the base of the flagella/cilia and progress with the same sequence towards the tip

Answer 109

Made of flagellin helix and rotated by a protein motor secured in the plasma One or more may be present Rotated like motar

Answer 110

Shorter but similar in structure to flagelli Project from cell surface Also allow attachment and exchange of genetic material

An Introduction to the Structure of Cells Flashcards

(148 cards)