Module 2 - Foundations in Biology Flashcards
(247 cards)
1
Q
Centrioles
A
Structures found in cytoplasm made of microtubules that produce spindle fibres during mitosis
2
Q
Chloroplasts
A
Organelles found in plants & algae that are site of photosynthesis
3
Q
Cilia
A
Small hair-like structures that project from surface of cells
4
Q
Confocal microscopy
A
Type of microscope that uses lasers to scan specimen point by point to produce image
5
Q
Cytoskeleton
A
Mesh of protein fibres found in cytoplasm of eukaryotic cells used for structural support & intracellular transport
6
Q
Differential staining
A
Using multiple different stains to distinguish different parts of a specimen
7
Q
Eukaryotic cell
A
Type of cell that contains a nucleus along with membrane bound organelles
8
Q
Flagella
A
Whip-like structure found on bacteria cells that is used for call movement
9
Q
Golgi apparatus
A
Organelle found in eukaryotic cells that is involved in the modification & packaging of proteins
10
Q
Light microscope
A
Type of microscope that uses series of lenses to magnify the visible light reflecting off a specimen
11
Q
Lysosomes
A
Membrane-bound vesicles found in cytoplasm that contains hydrolytic enzyme lysozyme
12
Q
Magnification
A
How much bigger an image appears compared to original object
image size=actual size x magnification
13
Q
Mitochondrion
A
Organelle found in eukaryotic cells that is the site of aerobic respiration
14
Q
Nuclear envelope
A
Double membrane that surrounds the nucleus
15
Q
Nucleolus
A
Structure found inside the nucleus that contains proteins & RNA & is involved in synthesising new ribosomes
16
Q
Nucleus
A
Organelle found in eukaryotic cells that stores genetic information of cells as chromosomes & is surrounded by a membrane called the nuclear envelope
17
Q
Plasma membrane
A
Semipermeable lipid bilayer studded with proteins that surrounds the cell & many organelles
18
Q
Prokaryotic cell
A
Type of cell that doesn’t contain any membrane bound organelles/nucleus
19
Q
Resolution
A
Ability to distinguish 2 different points in a specimen
20
Q
Ribosomes
A
Organelles found either free in cytoplasm/membrane bound
Involved in protein synthesis
21
Q
Rough endoplasmic reticulum (RER)
A
Membrane bound organelle that is involved in synthesis & packaging of proteins
22
Q
Scanning electron microscope (SEM)
A
Microscope that passes beam of electrons over surface of specimen to produce an image
23
Q
Smooth endoplasmic reticulum (SER)
A
Membrane bound organelle involved in lipid synthesis
24
Q
Transmission electron microscope (TEM)
A
Microscope that passes a bean of electrons through a sample to produce an image
25
Adhesion
Property of water molecule that creates an attraction between them & surface that they are in contact with
26
Amino acid
Monomers containing an amino group (NH2), a carboxy group (COOH) & a variable R group that makes up proteins
27
Amylopectin
Branched polysaccharide made up of alpha glucose monomers, joined by α-1,6 glycosidic bonds that makes up starch along with amylose
28
Amylose
Unbranched polysaccharide made up of alpha glucose monomers joined by α-1,4 glycosidic bonds that make up starch along with amylopectin
29
Anions
Ion with a negative charge
30
Benedict's test
Biochemical test used to detect presence of a reducing sugar in a solution & distinguish between solutions of different reducing sugar concentrations
31
Biuret test
Biochemical test that produces a purple colour when it is added to a solution containing protein
32
Cations
Ion with a positive charge
33
Cellulose
Linear polysaccharide that is main component of cell walls & is made of beta glucose molecules joined by β-1,4 glycosidic bonds
34
Chromatography
Technique used to separate different molecules in a solution by their different properties
35
Cohesion
Property of water that creates an attraction between them causing them to stick together
36
Collagen
Type of fibrous protein that provides strength to many different cell types & makes up connective tissue
37
Condensation reaction
Type of reaction that joins 2 molecules together with formation of a chemical bond involving elimination of molecule of H2O
38
Conjugated protein
Protein with a prosthetic group bound to it
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Elastin
Type of fibrous protein that allows tissues & blood vessels to stretch & return to their original shape
40
Fibrous protein
Class of long chain proteins that are generally insoluble in water & typically have structural roles
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Globular proteins
Class of spherical shaped proteins that are generally water soluble & typically have metabolic roles
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Glucose
Hexose monosaccharide that is main respiratory substrate in eukaryotes
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Glycogen
Highly branched polysaccharide that is used as main energy storage molecule in animals, made up of alpha glucose monomers joined by α-1,4 glycosidic bonds
44
Haemoglobin
Type of conjugated globular protein used to transport oxygen that is made up of 4 polypeptide chains, each containing a haem prosthetic group
45
Hexose monosaccharide
Simple sugar that contains 6 carbon atoms
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Hydrogen bond
Type of weak bond formed between an electropositive hydrogen and an electronegative atom e.g. oxygen
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Hydrolysis
Breaking a chemical bond between 2 molecules involving use of a water molecule
48
Insulin
Globular protein hormone that is made in pancreas in response to detection of high glucose levels in blood
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Iodine test
Biochemical test that produces blue/black colour when its added to solution containing starch
50
Keratin
Type of fibrous protein that provides strength to nails & hair
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Lactose
Disaccharide made of a molecule glucose & galactose joined by glycosidic bond
52
Lipid emulsion test
Biochemical test that produces cloudy emulsion when performed on lipids
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Maltose
Disaccharide made of 2 molecules of glucose joined by glycosidic bond
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Monomer
Individual unit that can be bonded to other identical monomers to make a polymer
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Pentose monosaccharide
Simple sugar that contains 5 carbon atoms
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Phopholipid
Type of amphipathic lipid made from molecule of glycerol bonded to 2 fatty acid molecules & phosphate group
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Polymer
Molecules made from many repeating monomers joined together
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Primary structure
Individual sequence of amino acids in a protein
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Quaternary structure
Structure only applicable to proteins with multiple polypeptide chains that describes the interaction of different chains
60
Ribose
Pentose monosaccharide with composes the backbone of RNA
61
Saturated fatty acid
Type of fatty acid molecule containing only single bonds between carbon atoms
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Secondary structure
Local interactions of amino acids in polypeptide chain
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Solvent
Liquid that solutes can dissolve in to form a solution
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Starch
Polysaccharide used for energy storage in plants that is made of alpha glucose joined together in forms of amylose & amylopectin
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Sucrose
Disaccharide made of molecule of glucose & fructose joined by a glycosidic bond
66
Tertiary structure
Way that the whole protein folds to make a 3D structure
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Triglyceride
Type of lipid formed from molecule of glycerol joined by ester bonds to 3 fatty acid molecules
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Unsaturated fatty acid
Type of fatty acid molecule containing at least 1 double bond in the carbon chain
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Adenosine triphosphate (ATP)
Nucleotide consisting of a molecule of ribose joined to the nitrogenous base adenine & 3 phosphate groups
70
Degenerate (genetic code)
Term used to describe fact that some amino acids can be coded for by multiple different codons
71
Deoxyribonucleic acid (DNA)
Double stranded polynucleotide that contains the genetic material of an organism & is made up of deoxyribonucleotide monomers joined together by phosphodiester bonds
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DNA nucleotide
Monomer that makes up DNA & consists of deoxyribose, nitrogenous base & phosphate group
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DNA polymerase
Enzyme that catalyses formation of phosphodiester bonds between nucleotides during the synthesis of a new DNA strand
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RNA polymerase
Enzyme that catalyses formation of phosphodiester bonds between nucleotides during the synthesis of a new RNA strand
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Helicase
Enzyme that catalyses the unwinding & unzipping of DNA in many processes like replication & transcription
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Messenger RNA (mRNA)
Type of RNA that carries genetic information from DNA in nucleus to ribosomes for translation
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Non-overlapping (genetic code)
Term used to describe fact that each base is only part of 1 codon is read 1 at a time in order
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Nulceotide
Monomer from which nucleic acids are made that consist of a pentose sugar, nitrogenous base & phosphate group
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Phosphodiester bond
Type of bond that joins nucleotides together to create polynucleitide
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Purines
Class of nitrogenous bases which are made up of 2 rings that adenine & guanine are members of
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Pyrimidines
Class of nitrogenous bases which are made up of a single ring that cytosine, thymine 7 uracil are members of
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Ribosomal RNA (rRNA)
Type of RNA that makes up ribosomes
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RNA nucleotide
Monomer that makes up RNA & consists of ribose, nitrogenous base & phosphate group
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Semi-conservative replication
Replication of DNA to produce 2 new DNA molecules which both contain 1 new strand & 1 old strand from original DNA molecule
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Transcription
Process of synthesising a new mRNA strand from a molecule of DNA
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Transfer RNA (tRNA)
Type of RNA that has 3 hairpin loops, anticodon for attachment to mRNA codon & an amino acid binding site & used to carry amino acids to ribosome
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Translation
Process of protein synthesis where complementary tRNAs carrying amino acids are brought to each codon in mRNA as it moves through the ribosome
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Triplet (genetic code)
Term used to describe that DNA is grouped into 3 base long codons that are read together & code for an amino acid
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Universal (genetic code)
Term used to describe that the same codon code for the same amino acid in all organisms
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Activation energy
Amount of energy needed for a reaction to happen
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Active site
Specific region on an enzyme where the substrate binds & reaction takes place
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Amylase
Enzyme that catalyses extracellular breakdown of starch
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Catalase
Enzyme that catalyses intracellular breakdown of hydrogen peroxide into O2 & H2O
94
Coenzyme
Type of cofactor that is bound loosely to an enzyme with weak interaction
95
Cofactors
Non-protein molecule that is needed for the effective functioning of an enzyme
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Competitive inhibitor
Molecule which binds to the active site of an enzyme & prevent the substrate from binding
97
Cyanide (CN-)
Metabolic poison which acts as an irreversible inhibitor of cytochrome oxidase, prevents respiration
98
End-product inhibitor
Method of enzyme inhibition where the product of an enzyme controlled reaction can bind to the enzyme and prevent it from working
99
Enzyme
Biological catalyst used to speed up rate of biochemical reactions without being used up/permanently altered
100
Enzyme-product complex
Temporary complex formed after the enzyme has catalysed the reaction but before the products have left the active site of the enzyme
101
Enzyme-substrate complex
Temporary complex formed when the substrate binds to the active site
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Extracellular reaction
Reaction that occurs outside of cells
103
Inactive precursor
Inactive form of an enzyme that cannot carry out its function until its activated
104
Induced fit hypothesis
Model of enzyme action that describes how once a specific substrate binds to the active site, the enzyme undergoes subtle conformational changes to fit the substrate better
105
Intracellular reaction
Reaction that occurs within cells
106
Lock & key hypothesis
Model of enzyme action that describes how the enzyme will only fit a substrate that has the correct complementary shape to the active site
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Metabolism
Sum of all the chemical reactions taking place in a cell
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Non-competitive inhibitor
Inhibitor which binds to a different part of an enzyme (allosteric site), which prevents enzyme from functioning
109
Prosthetic group
Type of cofactor that is bound tightly to an enzyme with strong interactions
110
Substrate specificity
Ability of an enzyme to catalyse only a specific reaction/set of reactions which have substrates complementary to the active site
111
Temperature coefficient (Q10)
Method of calculating an increase in reaction rate after a 10°c temp increase - calculated using:
Q10=R2/R1
112
Trypsin
Enzyme that catalyses the extracellular breakdown of proteins
113
Active transport
Active movement of substances from a low concentration to a higher concentration with the use of energy in the form of ATP
114
Amphipathic
Molecule with both hydrophobic & hydrophilic parts
115
Cell lysis
Bursting of a cell, particularly after the uptake of too much H2O into an animal cell through osmosis
116
Cholesterol
Mostly hydrophobic molecule that sits in the hydrophobic portion of the membrane & regulates membrane fluidity
117
Crenation
Shrinking of a cell when placed in a hypertonic solution due to large amounts of H2o moving out of the cell through osmosis
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Endocytosis
Bulk uptake of substances into a cell by invagination of membrane to form a vesicle trapping the substances inside the cell with use of energy in form of ATP
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Exocytosis
Bulk transport of substances out of a cell using a vesicle that fuses with the plasma membrane using energy in the form of ATP
120
Facilitated diffusion
Net movement of substances from a high concentration to a lower concentration through transport proteins without use of energy
121
Fluid mosaic model
Model that describes membrane structure as a sea of mobile phospholipid studded with various proteins
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Hydrophilic
Molecule which is attracted to H2O
123
Hydrophobic
Molecule that repels H2O
124
Integral membrane protein
Type of protein bound to the membrane strong interactions
125
Osmosis
Net movement of H2O across a partially permeable membrane from a region of high H2O potential to an area of low H2O potential without the use of energy
126
Peripheral membrane protein
Type of protein that is weakly bound to the surface of the membrane
127
Phagocytosis
Ingestion of solid material (pathogens & foreign matter) by phagocytic cells
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Phospholipid
Type of lipid formed by the condensation of 1 molecule of glycerol, 2 fatty acids & phosphate group
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Pinocytosis
Bulk uptake of liquids into a cell using energy in form of ATP
130
Plasmolysis
Effect produced by placing plant cells in a hypertonic solution causing the cell to shrivel from H2O loss, resulting in membrane pulling away from rigid cell wal
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Simple diffusion
Spreading out of substances from a high concentration to a low concentration without the use of energy
132
Turgid
Used to describe a cell that is swollen due to large amounts of fluid uptake
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Water potential (Ψ)
Measure of tendency of H2O molecules to move from 1 area to another measures in kPa
134
Acrosome
Organelle found in the head of sperm cells which is specialised to digest the outer coating of an egg cell during fertilisation
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Anaphase
3rd stage in mitosis, chromosomes are pulled apart to the poles of the cell by the spindle fibres
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Anaphase 1
3rd stage of meiosis where the chromosomes that make up bivalent are pulled apart to the poles of the cell by the spindle fibres
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Anaphase 2
7th stage of meiosis where the chromatids are pulled apart to the opposite poles of the cell
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Anucleate
Type of cell which doesn't have a nucleus
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Asexual reproduction
Production of genetically identical offspring from 1 parent through process of mitosis
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Bivalent
Pair of homologous chromosomes
141
Ciliated epithelium
Type of epithelium which has many fine protrusions (cilia), specialised for sweeping dirt & debris out of the body
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Crossing over
Exchange of genetic material between 2 chromosomes in a bivalent
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Cytokinesis
Division of cytoplasm at the end of mitosis to produce 2 new daughter cells
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Differentiation
Process where a cell develops certain features so that it is specialised to carry out a certain functions
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Dipoid
Cells with 2 copies of each chromosome
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Erythrocyte
Anucleate cell specialised to carry O2 from the lungs around the body (RBC)
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G1 checkpoint
1st checkpoint in the cell cycle which occurs just before end of G1 phase, commits the cell to division under favourable conditions
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G1 phase
1st growth phase in interphase where the cell synthesises proteins & RNA duplicates its organelles & increases in size before DNA replication in S phase
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G2 checkpoint
2nd checkpoint in cell cycle , occurs at end of G2 phase & checks that DNA was correctly replicated during S phase before the cell enters mitosis
150
G2 phase
2nd growth phase of interphase where the cell continues to increase in size & synthesize biomolecules
151
Gametes
Sex cells that have haploid nucleus & are produced through meiosis
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Gene loci
Location of a gene on a chromosome
153
Guard cells
Type of cell usually found in pairs that is specialised to control the opening/closing of stomata
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Haploid
Cells with only 1 copy of each chromosome
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Homologous chromosomes
2 chromosomes with similar gene loci but different alleles, 1 inherited from each parent
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Independent assortment
Source of variation in meiosis where the bivalent chromosomes can line up either way around on the metaphase plate
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Interphase
Largest part of the cell cycle where cells spend most of their time growing/synthesising biomolecules/preparing for mitosis
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M (Metaphase) checkpoint
Checkpoint occurring at the end of metaphase during mitosis which ensures all chromosomes have correctly attached to the spindle fibres & aligned at the metaphase plate
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Meiosis
Type of cell division used to produce gametes that produces 4 genetically different haploid cells
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Meristematic tissue
Type of plant tissue which contains stem cells & is usually found in the growing regions of the plant
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Metaphase
2nd stage in mitosis where the chromosomes attach to the spindle fibres & align in the centre of the cell along the metaphase plate
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Metaphase 1
2nd stage of meiosis where the recombinant chromosomes align on the metaphase plate
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Metaphase 2
6th stage of meiosis where the recombinant chromosomes align on the metaphase plate
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Mitosis
Division of a cell to produce 2 genetically identical daughter cells
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Multipotent
Type f stem cell which has the ability to differentiate into any cell type within a certain tissue in the body
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Neutrophil
Type of WBC with a multi-lobed nucleus which is specialised to engulf & destroy pathogens
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Organ
Group of specialised tissues working together to carry out a specific function
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Organ system
Group of specialised organs working together to carry out a specific function
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Palisade cell
Type of cell found in the leaves of plants which contains many chloroplasts & is specialised to carry out photosynthesis
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Phloem
Tissue found in plants which is specialised for transport of assimilates from their site of production of different parts of the plant where they are needed
171
Pluripotent stem cell
Type of stem cell which has the ability to differentiate into any cell type in the body
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Prophase
1st stage in mitosis where the nuclear envelope breaks down, the centrosomes move to opposite poles of the cell, the mitotic spindle begins to form & the chromosomes condense
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Prophase 1
1st stage of meiosis where the nuclear envelope breaks down the spindle fibres form & the chromosomes condense & form bivalents, where crossing over occurs
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Prophase 2
5th stage of meiosis where the nuclear envelope breaks down, spindle fibres form & chromosomes condense
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Recombinant chromosomes
Chromosomes produced by the crossing over & exchange of genes during metaphase 1
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Root hair cell
Type of cell that is found in the roots of cells which has a large SA & is specialised for the uptake of water & ions from the soil
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S (synthesis) phase
2nd phase in the cell cycle where the DNA in the cells is replicated
178
Somatic cells
Any cells that make up an organism, excluding sex cells
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Sperm cells
Male gamete which contains a long tail, an acrosome & lots of mitochondria & is specialised to fertilise an egg cell
180
Squamous epithelium
Type of epithelium which is only 1 cell thick & is specialised for rapid diffusion
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Stem cell
Type of undifferentiated cell which has the ability to divide many times & differentiate into many different cell types
182
Stomata
Small openings in leaves/stem of a plant that can be opened/closed by guard cells in response to varying conditions
183
Telophase
Final stage of mitosis where new nuclear envelopes begin to form around the separated sets of chromosomes
184
Telophase 1
4th stage of meiosis where the nuclear envelope reform around the separated chromosomes & they uncoil
185
Telophase 2
Final stage in meiosis where the nuclear envelopes reform around the separated chromatids & they uncoil
186
Tissue
Groups of specialised cells working together to carry out a specific function
187
Totipotent stem cells
Type of stem cell which has the ability to differentiate into any type of cell in the body/placenta
188
Xylem
Tissue found in plants which is specialised for the transport of water & dissolved minerals up the plant
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How you could prepare a temporary mount of tissue for a light microscope
1.Obtain thin section of tissue, using ultra tome
2.Place plant tissue in a drop of water
3.Stain tissue on slide to make structures visible
4.Add coverslip using mounted needle at 45° to avoid trapping air bubbles
190
How a light microscope works
1.Lenses focus rays of light & magnify the view of a thin slice of specimen
2.Different structures absorb different amounts & wavelengths of light
3.Reflected light is transmitted t the observer via the objective lens & eyepiece
191
How a transmission electron microscope (TEM) works
1.Pass high energy beam of electrons through a thin slice of specimen
2.More dense structures appear darker, absorb more electrons
3.Focus image onto fluorescent screen/photographic plate using magnetic lenses
192
How a scanning electron microscope (SEM) works
1.Focus a beam of electrons onto a specimen's surface using electromagnetic lenses
2.Reflected electrons hit a collecting device & are amplified to produce an image on a photographic plate
193
How a laser scanning confocal microscope works
1.Focus a laser beam onto a small area on a sample's surface using objective lenses
2.Fluorophores in the sample emit photons
3.Photomultiplier tube amplifies the signal onto a detector, an image is produced pixel by pixel in the correct order
194
Magnification equation
Actual size=image size / magnification
195
Why do samples need to be stained for light microscopes
-Coloured dye binds to the structures
-Facilitates absorption of wavelength of light to produce image
196
Magnification & resolution of a compound optical microscope
Magnification= x2000
Resolution= 200nm
197
Magnification & resolution of a TEM
Magnification= x500 000
Resolution= 0.5nm
198
Magnification & resolution of an SEM
Magnification= x 500 000
Resolution= 3-10nm
199
How to use an eyepiece graticule & stage micrometer to measure the size of a structure
1.Place micrometer on stage to calibrate eyepiece graticule
2.Line up scales on graticule & micrometer, count how many graticule divisions are in 100μm on the micrometer
3.Length of 1 eyepiece division=100μm / number of divisions
4.Use calibrated values to calculate actual length of structures
200
Structure of the nucleus
-Surrounded by a nuclear envelope, a semipermeable double membrane
-Nuclear pores allow substances to enter/exit
-Dense nucleolus made of RNA & proteins assembles ribosomes
201
Function of the nucleus
-Contains DNA coiled around chromatin into chromosomes
-Controls cellular processes: gene expression determines specialisation & site of mRNA transcription, mitosis, semiconservative replication
202
Structure & function of the endoplasmic reticulum (ER)
-Cisternae: network of tubules & flattened sacs extended from cell membrane & connects to nuclear envelope
-Rough ER: many ribosomes attached for protein synthesis & transport
-Smooth ER: lipid synthesis
203
Structure & function of golgi apparatus
Plantar sack of membrane-bound, flattened sacs, cis face aligns with RER. Molecules are processed in cisternae.
Vesicles bud off trans face via exocytosis
-Modifies & packages proteins for export
-Synthesises glycoproteins
204
Structure & function of ribosomes
Formed of protein & rRNS, Have large subunit which joins amino acids & small subunit with mRNA binding site
205
Relationship between organelles involved in production & secretion of proteins
Ribosomes that synthesise proteins are attached to RER, Golgi aligns with the RER
206
Structure of mitochondria
-Surrounded by double membrane
-Folded inner membrane forms cristae: site of electron transport chain
-Fluid matrix: contains mitochondrial DNA, respiratory enzymes, lipids, proteins
207
Structure of chloroplasts
-Vesicular plastid with double membrane
-Thylakoids: flattened discs stack to form grana, contain photosystems with chlorophyll
-Intergranal lamellae: tubes attach thylakoids in adjacent grana
-Stroma: fluid-filled matrix
208
Function of mitochondria
Site of aerobic respiration to produce ATP
209
Function of chloroplasts
Site of photosynthesis to convert solar energy to chemical energy
210
Structure of a lysosome
Sac surrounded by single membrane
Embedded H+ pump maintains acidic conditions
Contains digestive hydrolase enzymes
Glycoprotein coat protects cell interior
211
Function of a lysosome
-Digests contents of phagosome
-Exocytosis of digestive enzymes
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Structure + function of plant cell wall
-Made of cellulose microfibrils-mechanical support
-Plasmodesmata form part of apoplast pathway-allows molecules to pass between cells
-Middle lamella-separates adjacent cell walls
213
What is bacteria cell wall made of
Peptidoglycan (murein)
214
What is fungal cell walls made of
Chitin
215
Structure + function of centrioles
-Spherical group of 9 microtubules arranged in triplets
-Located in centrosomes
-Migrate to opposite poles of cell during prophase + spindle fibres form between them
216
Structure of cell-surface plasma membrane
-Fluid Mosaic Model
-Phospholipid bilayer with extrinsic + intrinsic proteins embedded
217
Function of cell-surface membrane
-Isolates cytoplasm from extracellular environment
-Selectively permeable to regulate transport of substances
-Involved in cell signalling/cell recognition
218
Role of cholesterol in plasma membrane
Steroid molecule connects phospholipids + reduces fluidity
219
Role of glycoproteins in plasma membrane
-Cell signalling/cell recognition (antigens)/binding cells together
220
Role of glycolipids in plasma membrane
-Cell signalling + cell recognition
221
Structure + function of flagella
-Hollow helical tube made of protein-flagellin
-Rotates to propel organism
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Structure + function of cilia
-Hairlike protrusion son eukaryotic cells
-Move back + forth rhythmically to sweep foreign substances away/enable cell to move
223
Function of cytoskeleton
-Provides mechanical strength
-Aids transport within cells
-Enables cell movement
224
How H bonds form between water molecules
Water is polar: O more electronegative than H, attracts electron density in covalent bond more strongly, forms O𝛿- & H𝛿+
Intermolecular forces of attraction between lone pair on O𝛿- of 1 molecule & H𝛿+ on adjacent molecule
225
Biological properties of water
-Reaches maximum density at 4
-High surface tension
-Incompressible
-Metabolite/solvent for chemical reactions
-High specific heat capacity
-High latent heat of vaporisation
-Cohesion between molecules
226
Why waters incompressible nature is important for organisms
Provides turgidity to plant cells
Provides hydrostatic skeleton for small animals
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Why ice floats on water & why its important for organisms
Ice is less dense than H2O, H bonds hole molecule in fixed position further away from each other
Insulated water in arctic climates so aquatic organisms survive
228
Why is high surface tension of H2O important for organisms
Slow H2O loss due to transpiration in plants
H2O rises high in narrow tubes, lowering demand on root pressure
Some insects can 'skim' across surface
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Why is water an important solvent for organisms
Polar universal solvent dissolves & transports charged particles involves in intra/extracellular reactions
230
Why are high specific heat capacity & latent of vaporisation important for organisms
Acts as temp buffer, enables endotherms to resist fluctuations in core temp to maintain optimum enzyme activity
Cooling effect when H2O evaporated from skin as sweat/from mouth when panting
231
Elements in Carbohydrates
Carbon
Hydrogen
Oxygen
232
Elements in Proteins
Carbon
Hydrogen
Oxygen
Nitrogen
Sulphate
233
Elements in Nucleic Acids
Carbon
Hydrogen
Oxygen
Phosphate
Nitrogen
234
Difference between ⍺-glucose & 𝛽-glucose
OH in alpha is below
ABBA
235
Properties of alpha glucose
-Small & water soluble=easily transported in bloodstream
-Complementary shape to antiport for co-transport for absorption in gut
-Complementary shape to enzymes for glycolysis=respiratory substrate
236
Ribose
Pentose sugar
Ring structure
237
What type of bonds form when monosaccharides react
1,4/1,6
2 monomers=disaccharide
Multiple monomers=polysaccharide
238
Structure & function of starch
Storage polymer of ⍺-glucose in plants
-Insoluble=no osmotic effect on cells
-Large=doesn't diffuse out of cells
239
Structure & function of glycogen
Main storage polymer of ⍺-glucose in animals
-1,4 & 1,6 glycosidic bonds
-Branched=many terminal ends for hydrolysis
-Insoluble=no osmotic effect & doesn't diffuse out of cells
-Compact
240
Structure & function of cellulose
Polymer of 𝛽-glucose, rigidity to plant cell walls
-1,4 glycosidic bonds
-Straight chain, unbranched molecule
-Alternate glucose molecules rotated 180°
-H bond, crosslinks between parallel strands form microfibrils=high tensile strength
241
Saturated fatty acids
-Contain single bonds
-Straight chain molecules, many contact points
-Higher melting point-solid at room temp
-Found in animal fats
242
Unsaturated fatty acids
-Contain double bonds
-'Kinked' molecules, fewer contact points
-Lower melting point-liquid at room temp
-Found in plant oils
243
Structure & function of triglycerides
-High energy:mass ratio=high calorific value from oxidation
-Insoluble hydrocarbon chain=no effect on H2O potential of cells & used for waterproofing
-Slow conductor of heat=thermal insulation
-Less dense than H2O=buoyancy of aquatic animals
244
Function of phospholipids
-Forms phospholipid bilayer in H2O=component of membranes
-Tails can splay outwards=waterproofing
245
Structure & function of cholesterol
Steroid structure of 4 hydrocarbon rings
Hydrocarbon tail on 1 side, hydroxyl group on other
Adds stability to phospholipid bilayer by connecting molecules & reducing fluidity
246
How polypeptides form
Condensation between amino acids-form peptide bonds
4 levels of protein structure
247
