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Biology-Corinna > Year One > Flashcards

Year One Flashcards

1
Q

What organelles do plants and animal cells have

A

Animal
Nucleus vesicles lysosomes mitochondria rough and smooth er Golgi Cytoplasm membrane ribosomes

Plant
Nucleus cell wall membrane chloroplasts vacuole plasmids cytoplasm vesicles Golgi ribosomes

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2
Q

What organelles do eukaryotic cells have?

A

Lysosome 80s ribosomes chloroplasts membrane bound organelles, nucleus nuclear envelope mitochondria nucleolus grana rough and smooth er centriole

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3
Q

What organelles do prokaryotic cells have

A

70s ribosomes circular DNA Muriel cell wall cell membrane cytoplasm starch granules glycogen lipid droplets capsule plasmids flagellum pili

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4
Q

What are characteristics of viruses

A 
Non living 
Can’t replicate on their own
Have lipid envelope
Capsid attachment proteins 
Receptors
Nuclei acid
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5
Q

How do viruses replicate

A

Identify host cell via their receptors and attach
Endocytosis:lipid envelope fuses with membrane
Capsid disintegrates releasing contents into host cell
Virus uses host cells machinery to replicate
New virus cell forms and buds off

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6
Q

What is a carcinogen

What is a mutagen

A

Carcinogen: causes growth of cancer

Mutagen: causes damage to cells

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7
Q

What happens in phase two of mitosis

A

PMAT
1-prophase=chromosomes condense, nuclear envelope breaks down, nucleolus breaks down, centrioles and mitotic spindle fibres form
2-metaphase=chromosomes line up on metaphase plate, chromatids will attach to spindle fibres via centromere to spindle fibres
3-anaphase=chromatids pulled apart to opposite poles of cell by mitotic spindle fibres
4-telophase= spindle fibres disintegrate, nuclear envelope and nucleus reforms, the chromosomes become diffuse and a cleavage furrow forms

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8
Q

What are characteristics of plasmids

A

When daughter cell replicates one may get more than other
Can get from environment
Replicate on own
Can be altered to get certain characteristics
Don’t associate with proteins

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9
Q

How does cancer occur

A

A gene controlling cell cycle mutates, causing rapid and uncontrolled growth of cells

A lump of abnormal unspecialised cells that overwhelm an organ forms a tumour

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10
Q

What does benign and malignant mean

A

Benign- not cancerous, slow grower

Malignant- cancerous and fast grower, undergoes metastasis (lump breaks off and travels as lump around body and can infect any organ)

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11
Q

What is a proto-oncogene?

A

A gene that promotes cell division

If mutates into oncogene, they act excessively and cells will divide rapidly and uncontrollably

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12
Q

What is a tumour suppressor gene

A

It inhibits cell growth so if it mutates then inhibition no longer happens and the cells uncontrollably grow and divide

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13
Q

What’s definition of mitosis

A

A parent nuclei undergoes nuclear division to produce to genetically identical daughter cells which are identical to eachother and the parent cell

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14
Q

What happens in phase one of mitosis

A

Interphase
G1-cell doubles in size, protein synthesis and contents replicate
S-DNA replication (semi conservative)
G2-cell checks for any errors in replication, grows more, prep for mitosis

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15
Q

What happens in phase 3 of mitosis

A

Cytokinesis

Parent cell splits and separates

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16
Q

What is a plasma membrane

A 
The boundary between cell contents and environment 
Made of phospholipids and proteins
Semi permeable cell surface membrane
Fluid
Reform if broken
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17
Q

What are the functions of cell surface membrane

A

Help maintain homeostasis
Control movement of substances in and out
Forms boundary between cell and environment allows for different conditions for different reactions inside and out of cell

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18
Q

What are functions of organelle membrane

A

Separates from rest of cell
Different environments different reactions
Surface area for reactions to occur on
Isolates enzymes

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19
Q

What’s function of a membrane protein

A 
Help in movement of ions or molecules
Cell recognition
Act as receptors
Help adhere to cells
Structural support
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20
Q

What’s simple diffusion

A

Diffusion not requiring energy in form ATP

Movement of non polar or lipid soluble molecules across bilayer

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21
Q

What is osmosis

A

The net movement of water from area or region of high water potential to region of low water potential through selectively permeable membrane

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22
Q

What is water potential

A

The potential of water to move across a semi permeable membrane, pressure of molecules

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23
Q

What is the role of active transport in the ileum

A

Prevents dynamic equilibrium being met
All glucose and amino acids absorbed
Na+ and k+ pump to maintain na+ conc grad

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24
Q

What is the role of diffusion in absorption

A

Maintain conc grad as cells use up glucose in blood
Glucose molecules move down conc grad into blood
Higher conc of glucose and amino acids in ileum so creates conc grad to blood

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25
Q

What is the reason for cholesterol in the plasma membrane

A

Adds strength
Keeps it less fluid but not rigid
Pulls hydrophobic tails together

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26
Q

What’s the function of gylcolipids in plasma membrane

A

Cell recognition
Helps adhere to other cells
Cell surface receptors
Stability

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27
Q

What’s the role of glycoproteins in plasma membrane

A

Cell recognition
Cell receptor
adhere

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28
Q

What’s facilitated diffusion

A

The movement of polar molecules down conc grad using carrier or channel proteins

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29
Q

What’s passive diffusion

A

Diffusion that doesn’t need energy eg facilitated and simple

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30
Q

Why is the plasma membrane called fluid mosaic

A

Fluid-contents constantly moving

Mosaic-proteins are randomly embedded and shaped

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31
Q

How does channel protein work

A

Ion or molecule bind to receptor

Channel opens, filled with water so polar molecules can dissolve

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32
Q

How does carrier protein work

A

Ion molecules binds to protein, causes it to change shape which releases it to other side

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33
Q

Facts about water potential

A

Closer to 0 the higher the potential

The higher the potential the less solutes in it

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34
Q

What happens to a cell when it’s put in a hypotonic solution

A

Animal Cell undergoes lysis

Plant cells swell and become turgid and no more water can enter

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35
Q

What is a hypotonic solution

A

Solution has a higher water potential than cell

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36
Q

What is a hypertonic solution

A

Has a lower water potential than cell

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37
Q

What happens to a cell in a hypertonic solution?

A

Animal cell will shrink and shrivel up

Plant cells protoplasm will pull away from cell wall cell is plasmolyzed

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38
Q

What happens to a cell in between plasmolyzed and turgid?

A

Incipient plasmolyzed or flaccid

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39
Q

How does co transport of glucose and na+ work

A

Na+ diffuses down conc gradient, the energy from this moves glucose against its gradient

Na+/k+ pump maintains na+ conc grad

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40
Q

What increases rate of absorption/movement across the ileum

A

Villi, microvilli increases surface area

Increased number of protein channels/carriers

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41
Q

What is large latent heat of vapourisation

A

Large increase in energy is needed to turn into vapour

Creates large cooling effect

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42
Q

What is large latent heat of fusion

A

A lot of energy needed to be lost to freeze

Insides/contents of cells will never freeze

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43
Q

What is a metabolite

What is a solvent

A

Metabolite-involved in chemical reactions

Solvent-what solutes (ionic or polar substances) dissolve in, transports nutrients

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44
Q

What is high specific heat capacity

A

A large amount of energy needed to increase temperature due to being extensive,y hydrogen bonded

Thermostable environment

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45
Q

What are characteristics of fatty acids

A

Insoluble/immiscible in water

Soluble in organic solvents

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46
Q

What is polymerisation

A

Joining of 2 amino acids in condensation reaction to form a peptide bond

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47
Q

What forms of glucose are needed to form

Maltose
Sucrose
Lactose

A

A glucose + A glucose
A glucose + Bfructose
Bgalactose + A glucose

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48
Q

What’s a hydrolysis reaction

What’s a condensation reaction

A

Addition of water to break up chains

Removal of water to make chains

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49
Q

What is the test for starch

A

Iodine solution goes black/blu

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50
Q

What’s the structure of amylose and amylopectin

A

AMYLOSE
A glucose,Helix,OH on inside,Insoluble, 1,4 glycosidic bonding

AMYLOPECTIN
14 & 16 glycosidic bonding, very branched, helix

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51
Q

What was the test for reducing sugars

A

Add Benedictus solution
Boil

Goes brick red if reducing sugar

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52
Q

Give examples of reducing and non reducing sugars

A

Reducing: all mono saccharides most disaccharides

Non reducing: sucrose

53
Q

What’s the test for non reducing sugars

A

Heat with HCL

Then add Benedicts

54
Q

What does a competitive inhibitor do?

A 
It binds with the active site and occupies it 
Prevents substrate binding with enzyme
Less E-S complex’s
Less successful collisions 
Slower rate reaction
55
Q

What does a non competitive inhibitor do?

A 
Binds to allosteric site 
Binding changes charges in active site
Enzyme denatured 
Substrate no longer fits
Less E-S complexes made
Less successful, collisions, slower rate of reaction
56
Q

What’s needed for enzyme to work

What are attractive forces

A

Substrate to fit
Physical contact

Pressure put in substrate to break and reform bonds to make products.

57
Q

What’s the difference between lock and key model and induced fit model

A

Lock and key: suggests enzyme is one specific shape

Induced fit: suggests active site is a generic shape and moods around substrate

58
Q

What are characteristics of lipids

A

Made of carbon, nitrogen, oxygen
Soluble in other organic solvents eg alcohol
Insoluble in water

59
Q

What are the characteristics of saturated and unsaturated fatty acids

A

Saturated:fit closely together, solid at room temp, high melting point, regular pattern, strong inter molecular forces

60
Q

Explain reducing sugar tests

A

Soluble blue Cu2+ ions reduced by anomeric carbons to Cu+

Cu+ ions form a brick red precipitate in presences of alkaline solution

61
Q

Characteristics of glycogen

A

Alpha glucose
Found in liver or muscle cells
1,6 bonding-shorter chains but extremely branched
Small granules

62
Q

What’s an anobolic and catabolic reaction

A

Anobolic: making/forming complex molecules

Catabolic: breaking down of molecules

63
Q

What are triglycerides made of?

What bond forms and how?

A

3 fatty acids combined with glycerol

Condensation reactions forms 3 Ester bonds to release 3 water molecules

Ester bond

64
Q

What are proteins made of?

A

Amino acids-hydrogen, oxygen, nitrogen, carbon, sulfur

65
Q

What’s starch made of

A

Amylose and amylopectin which are made of alpha glucose

66
Q

What are the types of proteins

A

Globular Fibrous
Haemoglobin. Collagen.
Ball shape Stable and strong
Compact Long chains
Enzymes Cross bridging
Soluble in water

67
Q

What are polymers, monomers

A

Monomer-individual building block

Polymer-2 or more joined

68
Q

What are the roles of proteins

A 
Hormones
Enzymes
Anti bodies
Cell membrane
Structural - collagen
69
Q

What’s the test of lipids

A

Emulsion test- dissolve in ethanol and shake, then add in cold water

70
Q

What are phospholipids

A

2 fatty acids, phosphate and glycerol

71
Q

What’s a bilayer

A

Made of phospholipids
Heads associate together and with water
Holds membrane together
Heads face out, tails inside

Hydrophobic Barrie

72
Q

What are the roles of lipids

A 
Protection
Insulation
Source of energy
Waterproofing
Cell membrane
73
Q

What’s a monosaccharide

A

Single building block of carbohydrates

74
Q

What are the functions of carbohydrates

A

Structural-cellulose cell walls

Energy source-starch glycogen

75
Q

What’s a disaccharide?

What reaction

A

Two monosaccharides joined together by glycosidic bonds formed in a condensation reaction

76
Q

What are amino acids?
What bond?
What’s its structure?

A

Building blocks of proteins, peptide bonds

Amino group - r group - carboxyl group

77
Q

How is energy gotten from starch and glycogen

A

Hydrolysis at ends of chains
Very compact lots stored in small place
Very branched so easy access, quick release

78
Q

What’s the structure of cellulose?

A

Parallel chains of b glucose hydrogen bond
Form microfibrils
Microfibres bond to form macrofibrils
Macrofibrils cross bridging to form cellulose

79
Q

What’s an anomeric Carbon

What’s a reducing agent

A

The reducing agent of a sugar-bonded to two oxygens

Gives electrons to something else

80
Q

What are the factors affecting enzyme action

A

Ph
Temp
Substrate conc
Enzyme conc

81
Q

What does an inhibitor do

A

It directly or indirectly interferes with the functioning of the active site of an enzyme
Less E-S complexes made
Less successful Collisions
Rate of reaction slows

82
Q

What is activation energy

A

Min amount of energy required to start a reaction
Enzymes lower activation energy
Reactions take place at lower temp

83
Q

What does polar mean

A

Uneven distribution of charges across molecule

Oxygen is more electromagnetic so pulls electrons to it

84
Q

What is cohesion

What is adhesion

A

Hydrogen bonds between water molecules between slight negative and slightly positive hydrogen and oxygen

85
Q

What is infection

What is immunity

A

Infection: interaction between pathogen and body’s defence mechanisms

Immunity: means by which the body protects itself from infection

86
Q

What defence mechanisms does the body have

A

Non specific. Specific
Physical barriers phagocytosis Cell mediated. Humoral response

87
Q

How does the body recognise self material

A

In fetes, lymphocytes constantly collide with cells
Infections are rare so only encounters self material
If lymphocytes have receptors that fit those of the bodies they undergo apoptosis or are suppressed

88
Q

What is phagocytosis

A

Secondary line of defence
1-Pathogens release chemical products which attract phagocyte
2-receptors of cell surface membrane of phagocyte recognise and bind to proteins on surface of pathogen
3-phagocyte engulfs pathogen by endocytosis to form a vesicles inside called phagosome
4-lysosome moves toward phagosome, fuse with it to form phagolysosome
5-lysosomes release their lysozymes, they hydrolyse the pathogens Cell walls
6-products broken down and are either absorbed into cytoplasm or expelled by exocytosis

89
Q

What is the first line defence

What’s second line defence

What’s third line defence

A

1-physical barrier eg skin
2-phagocytes
3-Cell mediated and humoral response

90
Q

What’s an antigen

A

Proteins that are part of cell surface membrane of organism or substance that’s recognised as non self by immune system and stimulates an immune response

91
Q

What are lymphocytes

A

Specific immune response
Type of white blood cell
Produced by stem cells in bone marrow

Two types: B-lymphocytes and T-lymphocytes

92
Q

What is cell mediated immunity

A

1-pathogen engulfed by phagocyte, hydrolysed. Pathogens antigen is presented on a MHC complex
2-T cell that has complimentary receptors to antigen bind to it (colonial selection)
3-Creates activation energy which activates clonal expansion of T cell
5-memory cells
-t helper cells
-tcells that stimulate phagocytosis
-tc cells-cytotoxic killer t cells

93
Q

What does a cytotoxic killer T cell do

A

Kills abnormal cells that are infected by pathogens
Produces performing which makes holes in cell surface membranes
Cell membranes become freely permeable to all substances, water moves in and bursts cell

94
Q

What is humoral immunity

A

1-B cell that’s complimentary (clonal selection) to antigen engulfs pathogen by endocytosis and presents antigen on a MHC complex
2-t helper cell binds to antigen, activation energy, stimulates B cell to divide and clone itself (colonial expansion)
3-memory cells
-plasma cells which produce monoclonal antibodies which are complimentary to antigen

95
Q

What is the structure of an antibody

A

4 polypeptide chains, 2 heavy and 2 light chains
Variable region is the antigen antibody complex
Constant region is the rest of antibody

96
Q

How do antibodies lead to destruction of pathogens

A
  • Mark pathogen by binding to antigen so phagocytes can destroy easier
  • agglutination of cells (clumps so easier to be located)
  • combine with toxins (prevent them from entering cells)
  • attach to flagelum (stop moving easily)
  • combine with toxins neutralising them
  • lysis if bacterial cells (“punch” holes in cell wall)
97
Q

How can antibodies be used in medical treatments

A

Direct monoclonal therapy

  • monoclonal specific to antigens on cancer cell produced
  • given to patient and they attach to receptors on cancer cells
  • attach to surface and block chemical signals that stimulate their uncontrolled growth
  • herceptin

Indirect therapy

  • radioactive drug or cytotoxic drug attached to antibody
  • when it attached to cancer cell it kills them
98
Q

How are antibodies used in pregnancy testing

A

HCG produced by pregnant women
1-urine travels up to first zone, HCG acts as substrate and binds to the mobile HCG antibodies that have a blue latex bead attached, form HCG antibody complex
2-urine travels to second zone, where immobile antibody is, binds with HCG antibody complex, blue beads appear a line if pregnant
3-if not pregnant no HCG so beads are swept past zones to the 3rd zone where bond to immobilised antibodies in control window

99
Q

What’s passive immunity

A

Introduction of antibodies into individuals from outside source. No direct contact with pathogen or antigen needed. Immunity acquired immediately.

No lasting effect, no memory cells no new antibodies - eg anti venom

100
Q

What’s active immunity

A

Natural - individual infected by disease under normal circumstances, body produces own antibodies

Artificial- basis of vaccination, induced immune response without individual suffering symptoms of disease

101
Q

How does HIV replicate

A
  • Travels in blood stream
  • attachment proteins in HIV readily bind to CD4 protein on t helper cell
  • lipid envelope fuses with cell surface membrane
  • capsid release contents
  • hiv reverse transcriptase converts RNA to dna
  • viral dna moves into nucleus via nuclear pore and is inserted to dna
  • viral dna creates messenger dna which contains instructions for production of viral contents
  • hiv particles made by ribosomes move to surface of t helper cell, then bud off using t helper cells surface membrane as their own
102
Q

How is aids caused

A

HIV kills or interferes with functioning of t helper cells
T helper cells can’t stimulate B cells
Adequate immune response not produced

103
Q

How do you work out SA:volume ratio

A

SA
———— == x:1
Volume

104
Q

What materials are exchanged by organisms

A

Respiratory gases
Nutrients
Excretory products
Heat

105
Q

Examples of passive exchange and active exchange

A

osmosis and diffusion

Active transport

106
Q

Features of specialised exchange surfaces

A

Large SA: volume
Very thin, short diffusion pathway,
Selectively permeable membrane
Movement of environmental medium to maintain diffusion conc
Transport system to ensure movement of internal to maintain conc grad

107
Q

What mechanisms do insects have for gas exchange

A

Spiracles
Internal network of tracheae which are supported by strentghened rings prevent collapsing
Tracheoles which extend out through all tissues
Short diffusion pathway for cells to tracheoles

108
Q

Why are ends of tracheoles filled with water

A

During major activity muscle cells respire anaerobicslly
Produce lactate
Lowes water potential of cells
Water moves from tracheoles into cells by osmosis taking dissolved gases with it
Volume water decrease, draws in more air

109
Q

What’s the structure of gills

A

Gill filaments are stacked
Gill lamella line filaments at right angles increasing surface area of gills
Water taken in through mouth over gills and out the operculum
Counter flow of water to blood

110
Q

What are the adaptations of leaves for rapid diffusion

A

Many stomata on underside
No cell far from stomata
Diffusion pathway short
Lots of air spaces in side, inter connecting air spaces throughout mesophyll, gases readily come into contract with mesophyll cells
Larger SA of mesophyll cells rapid diffusion

111
Q

How do guard cells control opening of stomata

A

In photophosphorylation, atp produced
Atp powers pumps that cause active tranpsport of k+ into guard guards
This lowers water potential so water moves in by osmosis, causing cells to swell and expand, as guard cells have thicker inside cell wall they bend creating gap in middle

112
Q

How is water loss limited in insects

A

Small sa : volume ratio
Waterproof covering - waxy cuticle
Spiracles close during periods of rest

113
Q

How are plants adapted to restricted water supply

A

Thick waxy cuticle - less water lost
Rolled leaves-stomata inside, still air, saturated with water, no gradient so water doesn’t move out
Hair leaves “. “
Reduced sa : volume ratio

114
Q

What structures make up the human gas exchange system

A

Trachea - rings of cartilage prevent collapsing
Lungs - rib cage protects them
Bronchi - produce mucus to trap dirt, ciliated walls
Bronchioles- lined with epithelial cells, walls of muscle
Alveoli - collagen and elastic fibres, one cell thick

115
Q

What happens in inhalation

A

1- external intercostal muscles contract, internal intercostal muscles relax
2-rib cage pulled upwards and out, increasing volume of thorax
3- diaphragm muscle contracts causing it to flatten further increasing volume of thorax
4-increase of volume decreases pressure, pressure inside is less than atmospheric pressure, air is forced inwards down its pressure gradient

116
Q

What’s the equation for pulmonary ventilation

A

Tidal volume x breathing rate

117
Q

Where does gas exchange in humans occur

A

On epithelial cells of alveoli

118
Q

How is human system adapted for efficient gas exchange

A

Alveolar walls one cell thick-short diffusion pathway
Network of capillaries which are one endothelial cell thick
Narrow capillaries-red blood cells pushed against wall short diffusion pathway
Large SA of alveoli-large area for diffusion
Constant ventilation of blood and air, maintain conc gradient

119
Q

What is the digestive system

A

Long muscular tube and associated glands

Hydrolyse large insoluble molecules into smaller soluble ones

120
Q 
What happens in each of the following 
Oesophagus 
Stomach 
Ileum 
Large intestine 
Salivary glands
A

O-peristalsis to push food bolus from mouth to stomach
S-muscular sac, stores and digests food eg proteins
I-further food absorption and digestion, enzymes produced by pancreas secrete into ileum, super folded walls
L-absorption of water and storage of faeces
SG-near mouth and produces salivary amylase

121
Q

What are the two stages of digestion

A

1-physical breakdown
By teeth creating larger SA for enzymes
Churned by muscles in stomach

2-chemical digestion’s
Enzymes hydrolyse insoluble molecules carbohydrase, lipase, protease

122
Q

What are the stages of carbohydrate digestion

A

Saliva enters mouth from salivary glands and is mixed with food through chewing
Saliva contains salivary amylase, starts hydrolysing starch into maltose
Food swallowed and enters stomach, amylase denatured
In Duodenum mixed with pancreatic juices-pancreatic amylase continues to hydrolyse. Bile neutralises acidic stomach conditions
Muscles in intestine wall push food into ileum, membrane bound maltase in epithelial membrane breaks maltose down into glucose

123
Q

What happens in lipid digestion

A

Small intestine broken down into micelles by bile
Lipids are emulsified
Lipase enzymes in pancreatic juices hydrolyse Ester binds to form fatty acids and glycerol

124
Q

What happens in protein digestion

A

Peptidases hydrolyse proteins into amino acids

  • endopeptidases hydrolyse central peptide binds forming shorter chains
  • exopeptidases in hydrolyse terminal peptide bomds to form dipeptides and monopeptidee
  • dipeptidases hydrolyse bonds between dipeptides, membrane bound enzyme in ileum
125
Q

Features of transport systems

A

Suitable medium to carry materials in normally liquid based
Form of mass transport
Closed system of tubular vessels
Mechanism of transporting medium within vessels

Achieved by
Animals :muscle contraction
Plants : natural passive movements

126
Q

What type of circulatory system do mammals have

A

Closed, double circulatory system as when passed through lungs it loses pressure and needs higher pressure to get around whole body

127
Q

Where does blood from right atrium go to

A

Through atrioventricular valve into ventricle, then out the pulmonary artery to lungs, then to pulmonary vein to left atrium, through atrioventricular valve to ventricle then up out aorta to body

128
Q

How does the heart get blood

A

Coronary arteries

129
Q

What happens in cardiac cycle

A

1- diastole
-blood returns to heart, atria relaxed, as they fill pressure builds once bigger than pressure below in ventricles, atrio valve opens
-blood passage aided by gravity
2-atrial systole
-contraction of Atria along with recoil or relaxed ventricle walls forces remaining blood into ventricles
3-ventricular systole
-short delay, walls contract simultaneously
-increase pressure so it’s higher within them than in atria, forces shut atrio valves, pressure increase more so it’s higher than artery and aorta
-opens semi lunar valves and then contraction forces blood out ventricles.

Biology-Corinna (22 decks)

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