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Biology Yr 11 > Cells > Flashcards

Cells Flashcards

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1
Q

Description of cell wall

A

Rigid, tough, made of cellulose

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2
Q

Description of cell membrane

A

Thin, covering, protects cells

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3
Q

Description of cytoplasm

A

Jelly like substance that contains organelles

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4
Q

Describe nucleus

A

Dense, ball shaped structure, contains DNA

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5
Q

Describe nuclear membrane

A

Thin covering over the nucleus

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6
Q

Describe nuleolus

A

Small dark area in the nucleus

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7
Q

Describe chromatin

A

In the nucleus, made of DNA and protein, contains genes

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8
Q

Describe endoplasmic reticulum

A

Clear, tubular system of tunnels throughout the cell

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9
Q

Describe ribosome

A

Small specks made of RNA. Found in cytoplasm or on the endoplasmic reticulum

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10
Q

Describe mitochondria

A

Location in the cytoplasm, bean shaped

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11
Q

Describe vacuole

A

Large open storage area Smaller in animal cells

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12
Q

Describe chloroplast

A

Green structures that contain chlorophyll

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13
Q

Describe Golgi body

A

Small bags with tubes connecting them

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14
Q

Describe lysosome

A

Small round structures containing enzymes

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15
Q

Descibe centriole

A

Small cylindrical

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16
Q

Function of cell wall

A

Protects and supports cell

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17
Q

Function of cell membrane

A

Protects cell Performs active and passive transport Moves material in and out of cell Communication

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18
Q

Function of cytoplasm

A

Pads and supports organelles inside cell Moves by cyclosis

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19
Q

Function of nucleus

A

Controls all of cells activities

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20
Q

Function of nuclear membrane

A

Covers and protects nucleus

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21
Q

Nucleolus

A

Produces ribosomes

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22
Q

Function of chromatin

A

Provides instructions for cells activities ( growth, reproduction)

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23
Q

Function of endoplasmic reticulum

A

Transports materials like proteins around cells

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24
Q

Function of ribosomes

A

Makes proteins

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25
Q

Function of mitochondria

A

Supplies energy or ATP for cell through cell respiration using glucose and oxygen

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26
Q

Function of vacuole

A

Storage tank for food,water, wastes or enzymes

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27
Q

Function of chloroplast

A

Captures sun light and uses it to produce food through photosynthesis

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28
Q

Function of golgi body

A

Packages and stores proteins for use in and out of cell

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29
Q

Function of lysosome

A

Digests older cell parts, food or other objects

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30
Q

Function of centriole

A

Used with spindle apparatus during cell mitosis

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31
Q

Do animals, plants or both have cell walls?

A

Plants

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32
Q

Do animals, plants or both have a cell membrane

A

Both

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33
Q

Do animals, plants or both have a cytoplasm

A

Both

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34
Q

Do animals, plants or both nucleus

A

Both

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35
Q

Do animals, plants or both nuclear membrane

A

Both

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36
Q

Do animals, plants or both Nucleolus

A

Both

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37
Q

Do animals, plants or both cromatin

A

Both

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38
Q

Do animals, plants or both endoplasmic reticulum

A

Both

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39
Q

Do animals, plants or both ribosome

A

Both

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40
Q

Do animals, plants or both mitochondria

A

Both

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41
Q

Do animals, plants or both vacuole

A

Both

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42
Q

Do animals, plants or both chloroplast

A

Plant

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43
Q

Do animals, plants or both Golgi body

A

Both

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44
Q

Do animals, plants or both lysosome

A

Both

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45
Q

Do animals, plants or both centriole

A

Animal

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46
Q

What is the cell theory

A
  1. all living things are composed of one or more living cells 2. All cells come from pre existing living cells
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47
Q

What are living things characterised by?

A

Move Grow Replicate/ reproduce Use energy from food Remove waste

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48
Q

Describe prokaryotic cells

A

Approximately 1-10 manometers long Approx 0.2-2 manometers in diameter Single celled organisms Grouped into Bactria and archaea

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49
Q

What do prokaryotic cells have?

A

Cell wall Plasma membrane Cytoplasm Chromosome DNA Plastic DNA Ribosomes Capsule Bactria flagellum Pili

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50
Q

What is endosymbiosis theory

A

Karyotic cells formed when bacterial cell was ingested by another primitive prokaryotic cell

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51
Q

What are the four biomacromolecules?

A

Lipids (eg: triglyceride) Nucleic acid (eg: DNA) Protein (eg: enzymes) Carbohydrates (eg: polysaccharides: starch)

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52
Q

What small organic compounds do cells assemble biomacromolecules from?

A

Simple sugars (monosaccharides: glucose) Fatty acids & glycerol Amino acids Nucleotides

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53
Q

Define autotrophs

A

Build own organic compounds from surrounding inorganic compounds they take in (e.g. photosynthesis)

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54
Q

Define heterotrophs.

A

Build biomacromolecules from existing organic compounds (e.g. chemical energy from food)

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55
Q

Define monomers.

A

Small molecules that act as building blocks for macromolecules

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56
Q

Define polymers

A

Large molecules built up from linking monomers

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57
Q

Equation for carbohydrates

A

nC H₂O

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58
Q

3 types of carbohydrates

A

Monosaccharides: glucose Disaccharides: sucrose = glocose + fructose Polysaccharides: cellulose

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59
Q

What does photosynthesis produce?

A

Glucose (monosaccharide)

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60
Q

What are glycoproteins made from?

A

Carbohydrates and protein

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61
Q

Are lipids soluble or insoluble in water?

A

Insoluble

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62
Q

Examples of lipids

A

Fats & oils; waxes Phospholipids; glycolipids; steroids

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63
Q

3 functions of lipids

A

Store energy (they have approximately twice the amount of energy as carbohydrates) Structural component of membranes Specific biological functions (chemical signal transmission)

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64
Q

What are most fats and oils?

A

Triglyceride (fatty acid & glycerol)

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65
Q

What are proteins essential for?

A

Virtually every cell process

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66
Q

What elements are in proteins?

A

C, H, O, N

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67
Q

What are proteins made up of?

A

Amino acids

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68
Q

How many types of proteins are there?

A

20 (another 2 found only in microbes)

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69
Q

What do plants do to their amino acid?

A

Synthesise it

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70
Q

Where do animals get certain amino acids and how many

A

Diet 9

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71
Q

Define proteome

A

Entire set of proteins produced by a cell

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72
Q

How are polypeptide chains made

A

Amino acids are linked by peptide bonds to form a polypeptide chain

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73
Q

What is order of amino acids determined by?

A

Genes in our chromosomes

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74
Q

How are proteins given characteristic features

A

Polypeptide chains fold

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75
Q

Define functional proteome mix

A

Study of what proteins do in differs cells and tissues

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76
Q

What is nucleic acid made up of

A

DNA and RNA

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77
Q

What does nucleic acid undertake

A

Many tasks at one time

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78
Q

Where is nucleic acid located

A

In nucleus

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79
Q

How large is DNA

A

Approx 2 m in every cell

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80
Q

Where is Nucleolus located

A

Nucleus

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81
Q

What does Nucleolus make

A

Ribosomal RNA ( form of nucleic acid)

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82
Q

What does ribosomal RNA make

A

Ribosomes

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83
Q

What is biological significance of low viscosity of water

A

Flows through small places and capillaries Enables aquatic organisms to move through it without using a lot of energy

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84
Q

What is biological significance of colourless and transparency of water

A

Light penetrates tissue and aquatic environments Allows photosynthesis to continue at considerable depths in aquatic environment

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85
Q

What is biological significance of water as universal solvent

A

Medium for chemical reactions of life Main transport medium in organisms

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86
Q

What is biological significance of ice being less dense that water

A

It floats Insulates underlying water

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87
Q

What is biological significance of lipids

A

Store of concentrated energy Insulation and transport fat soluble vitamins Phospholipids make up cellular membranes

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88
Q

What is biological significance of carbs

A

Major component of most plant cells Source of energy and involved in cellular recognition Can be converted into fats

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89
Q

What is biological significance of nucleic acids

A

Encode genetic info for construction and functioning of organism

90
Q

Biological function of monosaccharides

A

Energy source for fuelling cellular metabolism Eg glucose for respiration

91
Q

Structure one biological role of starch

A

Made up of branch cells of glucose Energy storage in compound in plant cells Concentrated in soluble starch granules

92
Q

Structure and bio role of glycogen

A

Made up of highly branched chains of glucose Energy storage compound in animal tissues

93
Q

Structure and bio role of cellulose

A

Long un-branched chains of glucose Major structural component of plant cells

94
Q

Structure and bio role chitin

A

Made up of unbranched chains of n-modified glucose Found in cell walls of fungi Main component of arthropod exoskeletons

95
Q

Basic structure of neutral fat triglyceride

A

Most phospholipids consist of lesser role attached to fatty acid chains and a phosphate group Phosphate water soluble whilst fatty acid is water repellent ( Hydrophobic )

96
Q

Why do lipids have high energy content

A

High proportion of hydrogen present in fatty acid chains When molecule metabolised chemical energy released

97
Q

Basic repeating unit of nucleic acids

A

Nucleotides are repeating monomers that from nucleic acid polymers

98
Q

Describe structure of nucleotides

A

Sugar molecule Nitrogenous space Phosphate group

99
Q

How info encode in DNA

A

Base sequence making strand of DNA provides genetic code for cell Precise sequences instruct cell to produce proteins and RNA products required to govern metabolism

100
Q

What makes each of the amino acids in proteins unique

A

The R group

101
Q

Primary structure of protein

A

Sequence of amino acids in polypeptide chain

102
Q

What determines primary structure of protein

A

Order of nucleotides in DNA and RNA

103
Q

How do sequence an composition of amino acids in protein how protein folds up

A

Differences between amino acids are due to different properties of R group These cause different kinds of intramolecular bonding between amino acids in polypeptide chain which influences way polypeptide chain will fold up

104
Q

Type of bond joining amino acids together

A

Peptide bond

105
Q

How is peptide bond formed

A

Condensation reaction

106
Q

Hoe are Di - and polypeptides broken down

A

Hydrolysis

107
Q

How r proteins involved in structural tissues of the body

A

Form important component of connective tissues and epidermal structures, cell membranes and in DNA packing

108
Q

How r proteins involved in catalysis metabolic reactions in cells

A

Enzymes involved in most metabolic reactions

109
Q

How does shape of fibrous protein relate to its functional role

A

Tertiary structure produces long fibres or sheets with many cross linkages Makes them very tough physically and ideal as structural molecules

110
Q

How does shape of catalytic protein (enzyme) relate to its functional role

A

3D structure produces globular shape with specific active site critical to their interaction with other molecules and their catalytic activity

111
Q

3 ways in which enzymes differ from other catalysts

A

Highly specific to particular molecule or bond type Work faster Sensitive to extremes in ph and temperature Generally easily denatured Sensitive to inhibition by metabolic poisons

112
Q

Why are enzymes so effective a low concentrations

A

Can be reused time and time again Not consumed by reaction

113
Q

How do enzymes catalyse reactions

A

Influencing stability of bonds in reactants or by providing an alternative reaction pathway

114
Q

How does heat denature enzymes

A

Changing its tertiary structure usually by disrupting stabilising bonds so that active site can no longer bind a reactant

115
Q

Is every cell and independent unit in an organism

A

Yes

116
Q

Define plasma membrane

A

Insoluble boundary of all living cells that maintains contents of cell and regulates movement of substances in and out of cell

117
Q

What have a plasma membrane an cell wall

A

Plants Bacteria Algae Fungi

118
Q

What do animals only have

A

Plasma membrane

119
Q

Is a cell wall permeable or impermeable

A

Permeable to most substances Selectively permeable

120
Q

Why is selective permeability important

A

Keeps optimal internal environment stable Removes waste Takes in necessary molecules and irons

121
Q

What does plasma membrane control

A

Exchange of material between internal and external environments of cell

122
Q

What are all cells contained by

A

A plasma membrane

123
Q

Describe plasma membrane

A

Flexible and porous Made up primarily of phospholipids and proteins

124
Q

Define hydrophilic head

A

Phosphate (water absorbing/dissolving)

125
Q

Define hydrophobic end

A

Fatty acid chains (avoid water/can’t dissolve)

126
Q

What is the current accepted model for plasma membrane structure

A

Fluid mosaic model

127
Q

What does the fluid mosaic model describe membranes as

A

Lipid bilayer which can flow and change shape Specialised proteins imbedded in lipid in various patterns

128
Q

What is the plasma membrane made more flexible by

A

Cholesterol in animals Phytosterol in plants and bacteria

129
Q

What are the different proteins imbedded in plasma membrane

A

Adhesion Transport Receptor Recognition

130
Q

Define adhesion proteins

A

Help link cells together

131
Q

Transport proteins

A

Carry molecules across membranes

132
Q

Receptor proteins

A

Binds hormones and other signal molecules

133
Q

Recognition proteins

A

Acts as a marker on proteins

134
Q

Antigens

A

Recognition proteins or glycoproteins combined with a carb chain

135
Q

What do antigens allow immune system to do

A

Recognise own cells

136
Q

What are the two types of transport

A

Passive and active

137
Q

Passive transport

A

Movement of irons and molecules across a membrane from high to low concentration No energy required

138
Q

Active transport

A

Transport of substances across membrane from low to high concentration Requires energy

139
Q

Diffusion

A

Spreading out of particles so they are distributed over space available Movement of irons and molecules from high to low concentration until reach equilibrium

140
Q

Diffusion occurs in what and why

A

Gases and liquids Molecules constantly moving

141
Q

Define met diffusion

A

Movement of gas and liquid molecules from high concentration to low concentration along a diffusion gradient

142
Q

Why is it called net diffusion

A

Some molecules will randomly move against the gradient

143
Q

Define passive diffusion

A

Down a concentration gradient

144
Q

Particle move how

A

Randomly at equal rates in all directions

145
Q

Facilitated diffusion

A

Passive process that requires substance to be attached to specific carrier molecule to move across membrane Charged particles Na + CL - Large molecules glucose,amino acids

146
Q

What my carry molecules be

A

Carrier proteins Channel proteins

147
Q

Osmosis

A

Movement of water across selectively permeable membranes from regions of low solute to high solute concentration

148
Q

Most important solvent in human body is what

A

Water (universal solvent)

149
Q

Define solvent

A

Substance in which another substance can dissolve to create a solution

150
Q

Define solute

A

Substance that can be dissolved in another substance

151
Q

Dilute solution

A

High concentration of solvent to solute particles

152
Q

Concentrated solution

A

Low concentration of solvent to solute particles

153
Q

Hypotonic solution

A

Low solute concentration Water goes into eukaryotic cells

154
Q

What do Eucaryotes have to remove excess water?

A

Contractile vacuoles Maintain osmotic balance by collecting water and emptying from self

155
Q

Hypertonic solution

A

High solute concentration Water leaves eukaryotic solution and cells shrink

156
Q

What do vacuoles in plants contain

A

Sap

157
Q

Why are turgid cells important in plants

A

Maintain shape and form

158
Q

Turgid

A

Tight and rigid from absorbed water

159
Q

Define hypotonic solution

A

Full turgor on plant cells

160
Q

What happens in Hypertonic solution

A

Vacuole shrinks Cell becomes flaccid Membrane pulls away from cell wall (plasmolysis)

161
Q

What do transport proteins use ATP for?

A

To move molecules or ions up their concentration gradient Eg: sodium-potassium pump

162
Q

What is sometimes required during active transport?

A

Bulk transport of particles across plasma membrane

163
Q

Define endocytosis

A

Movement of solids or liquids into cell from environment via vesicle formation

164
Q

Define exocytosis

A

Movement of solids or liquids out of a cell to the environment via vesicle formation

165
Q

What happens for vesicle to be suspended in cell’s cytoplasm?

A

Cell membrane folds around droplet of liquid or solid particle until completely enclosed. Newly formed vesicle pinches off.

166
Q

What are liquids called in regard to endocytosis?

A

Pinocytosis

167
Q

What are solids called in regard to endocytosis?

A

Phagocytosis

168
Q

Examples of phagocytosis

A

Amoeba eating Macrophage engulfing bacteria

169
Q

Define exocytosis

A

When contents of vesicle inside cell are passed to the outside

170
Q

How does exocytosis occur?

A

Vesicle that’s formed inside cell migrates to cell membrane and fuses with membrane. Contents of vesicle push out into extra cellular fluid

171
Q

Egs of exocytosis

A

Animals: hormones, mucus, milk proteins, digestive enzymes to other parts of animal Plants: Growth regulators toxins and macromolecules to other parts of plants

172
Q

What does physical and chemical nature of a substance determine

A

Way in which it will be transported across membranes by cells

173
Q

Chemical factors influencing cell material transport

A

Uncharged molecules dissolve easily in phospholipid bilayer Charged molecules require transport proteins call iron channels

174
Q

Physical factors influencing cell material transport

A

Size and charge affect rate of diffusion across membrane

175
Q

Impact of concentration gradient on substances

A

Diffuse more rapidly the higher the concentration gradient

176
Q

How does surface area to volume ratio affect how cell removes waste and supplies metabolic requirements

A

The larger surface area to volume ratio the more efficient cell is at removing waste and supplying metabolic requirements

177
Q

How do cells deal with issues of surface area to volume ratio

A

Changing shape

178
Q

Give example of how cells deal with issues of surface area to volume ratio by changing shape

A

Root hairs ( increased surface area) Biconcave red blood cells( increase surface area)

179
Q

How big are most human cells

A

10-15 nano meters

180
Q

Why is there a limit to cell size

A

All requirements of cell and products of cell must pass across cell membrane Therefore relationship between surface area and volume is important

181
Q

Define metabolism

A

Process cells carry out to keep organism alive

182
Q

How do cells assemble, rearrange and breakdown organic compounds

A

Chemical reactions

183
Q

What do internal cellular membranes allow

A

Many chemical reactions to occur at the same time

184
Q

Function of membrane bound cellular structures

A

Storage of products Concentration of reactants

185
Q

Increased surface area of membrane bound cellular structures allows for what

A

More enzymes available for chemical reactions

186
Q

Define metabolic pathways

A

Ordered enzyme regulated reaction sequences

187
Q

What are main metabolic pathways that transfer energy through living systems

A

Photosynthesis Respiration

188
Q

What are the two chemical reactions in metabolism

A

Catabolism Anabolism

189
Q

Define catabolism

A

Chemical reactions that break down large organic molecules into smaller ones with release of energy

190
Q

Define anabolism

A

Process of combining small molecules to make larger ones Requires energy Also known as synthesis

191
Q

What is metabolism concerned with

A

Maintaining balance between energy release and energy utilisation

192
Q

Endergonic reactions use what

A

Energy

193
Q

Exergonic reactions do what

A

Release energy

194
Q

Energy for exergonic reactions do what

A

Fuel endergonic reactions

195
Q

Define enzymes

A

Proteins that allow chemical reactions to take place

196
Q

Importance of enzymes in body

A

Reactions would be too slow to be of use

197
Q

Define activation energy

A

Energy needed to get chemical reactions started

198
Q

How do enzymes effect activation energy

A

Reduce activation energy needed to begin a reaction

199
Q

Define biochemical pathways

A

Series of regulated steps in which chemical reactions in cells occur

200
Q

Define catalysts in living organisms

A

Called enzyme Increase reaction rates

201
Q

What does molecular structure of protein determine

A

How the perform their functions

202
Q

The active site for an enzymes has a highly specific shape for a what

A

Particular substrate to which enzyme attaches

203
Q

Define active site

A

Part of enzyme molecule that combines with substrate

204
Q

Define enzyme substrate complex

A

When enzyme and substrate combine

205
Q

How are induced fit models different to lock and key models

A

Enzyme shape not fixed Active site and substrate do not match initially Active site changes shape Chemical properties of substrate change so reaction can occur

206
Q

How fast do enzymes work

A

Very rapidly

207
Q

How do reactions affect enzymes

A

They are not destroyed or altered but can be reused

208
Q

What direction of a metabolic reaction can enzymes work in

A

Either

209
Q

When do enzymes work best

A

When cellular environment stays within limited range of temp and ph

210
Q

What influences enzyme activity

A

Temperature

211
Q

Enzymes are very sensitive to what

A

Ph of medium

212
Q

What happens when temp higher than enzymes range

A

Enzyme denatured and can’t work again

213
Q

What happens when temp lower than enzymes range

A

Rate of reaction slows down but enzyme not destroyed

214
Q

Define enzyme inhibitors

A

Substances that slow down or stop enzyme activity

215
Q

What can enzymes be inhibited by

A

Large amount of substrate Competitive inhibitors binding to active site

216
Q

What do cells use inhibitors for

A

Control reactions Produce specific amounts

217
Q

What do many enzymes require before they catalyse a reaction

A

Cofactors Presence of certain irons or nonprotein molecules

218
Q

What do cofactors do to shape of active site

A

Change it so enzyme combines with substrate

219
Q

Define coenzymes

A

Cofactors that are nonprotein organic molecules Eg vitamins

220
Q
A
221
Q
A

Biology Yr 11 (4 decks)

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