Unit One Flashcards
What is a somatic cell
Is every cell in the body other than the cells involved in reproduction
Where are somatic cells found
Everywhere in the body
What produces the most somatic cells
Mitosis
How many chromosomes are in a somatic cell
46
Give examples of different types of tissue that form organs (3)
Muscle tissue
Nervous tissue
Epithelial tissue
Can mutations be passed onto offspring
They cannot be passed on
What is a germline cell
Gametes sex cells
Where are germline cells found (3)
In reproductive organs
Bone marrow
Embryo
What produces more germline cells
Meiosis
How many chromosomes are in a germline cell
23
Can mutations in germline cells be passed onto offspring
Yes
Describe meiosis
•homologous chromosomes separated
•chromosomes separated into single chromatids
What is differentiation
The process by which cells become specialised by switching on and off genes
What is a gene expression
Allows a cell to carry out specialised functions
Give examples of differentiated cells
Sperm cells
Nerve cells
Red blood cells
What are stem cells
Unspecialised aromatic that can decide to make copies of themselves and/or differentiate into specialised cells
What are the different types of stem cells
Embryonic
Tissue (adult)
What is the difference between multi potent and pluripotent stem cells
Pluripotent can become any somatic cell in the body
Where do you find tissue stem cells
Bone marrow
Why can tissue stem cells not specialise into ALL types of cells
They are multi potent
What types of cells can tissue stem cells turn into (4)
Red blood cells
Phagocytes
Lymphocytes
Platelets
State two uses of stem cells
Corneal repairs
Regents ration of damaged skin
How is a cancerous tumour formed
When cancer cells divide excessively
What type of signals may fail to work on tumour
Regulatory signals
What is metastasis
When the cancerous cells get in the blood stream
What three structures make up a dna nucleotide
Phosphate
Deoxyribose sugar
Base
How does a nucleotide look
A Phosphate Circle top left connected by a line to a house shape of deoxyribose sugar on the 5 carbon which is connected to a rectangle base
In a nucleotide what are attached to the carbon 1base
Carbon 5 base
1 -base
5- phosphate
How are nucleotides held together
Though hydrogen bonds
State the stages involved in the DNA replication
DNA is unwound
hydrogen bonds between bases break to form two template strands
A primer bunds to the three end of the template DNA strand
DNA polymerase adds DNA nucleotides using complementary base pairing to the 3’end of the new DNA strand which is forming
DNA polymerase can only add DNA nucleotides in one direction
This means that the leading strand(with the 3’s at the end) is replicated continuously and the lagging strand (with 5 at the end) is replicated in fragments
Fragments of DNA are joined together by the enzyme Ligase
What are the requirements for DNA replication
Primers
DNA
ATP
Enzymes dna polymerase+ ligase
4 types of dna nucleotide
PDA4E
What is the name of the procedure used to amplify DNA
Polymerase
Chain reaction
Pcr
Requirements for DNA amplification
DNA primers,
DNA(as template),
a supply of 4nuclotides
heat tolerant DNA polymerase
PD4(HDP)
How are specific target sequences located
Primers
How is the DNA double helix separated into two strands
DNA is heated to 92-98 to seperate
How is the region of DNA replicated
Primers bind to target section of DNA end 3
nucleotides are added by DNA polymerase
Why are repeated cycles of cooling and heating used
amplify the target region of DNA
What happens when dna is heated between 92-98
Break the H bonds between bases and separated two stands
What happens when DNA is cooled between 50-65
Allows primers to bind to their complementary target sequences
What happens when the DNA is heated between70 and 80
Heat tolerant dna polymerase to replicate the region of dna
What are practical uses of pcr
Help solve crimes
Set the paternity suits
Test for viruses
Diagnose genetic disorders
What is meant by the term cell genotype
The genes that the cells have
What determines cell genotype
Alleles (DNA)
What what is meant by the cell phenotype
The physical appearance of a cell
What is meant by the term gene expression
Which genes are switched on and off
Are all genes expressed within a cell
No all of them
What controls gene expression
Nucleus
What influences gene expression
Mutagenic agents
Why are hr order of bases in DNA important
Order of amino acids
Why are the sequence of amino acids in a protein important
Because the different proteins made
State four bases found in RNA
Cytosine gamine adenine and uracil
Describe the shape of RNA
Single stranded and is composed of 4 nucleotides being phosphate- ribose sugar, 4 bases
What is the role of mRNA
Carries chemical messages from nucleus to ribosome
What is the role of rRNA
Ribosomal RNA binds to proteins to form a ribosome
What is the role of tRNA
Carries a specific amino acid to a ribosome
Where does transcription occur
DNA in the nucleus
List the stages involved in transcription
RNA polymerase moved along the DNA unwinding the double helix and breaking the hydrogen bonds between the bases
RNA polymerase synthesis a primary transcript of RNA
What is the difference between introns and exons
Introns are non-coding regions
Exons are coding regions
Where do you find introns
DNA
What is the difference between the primary and mature transcript of RNA
Primary -introns
Mature- exons
Where does the mature transcript travel to
Leave the nucleus enters the cytoplasm and attaches to a ribosome
What is a mRNA codon
Three bases of tRNA complementary to mRNA
State the relationship between mRNA codons and tRNA anticodons
Complementary
What is the specific role of tRNA
To transport specific amino acids to ribosome
How do mRNA codons and tRNA anticodons translate the genetic code
They will bond and create a poly peptide
What is a polypeptide
Lots of amino acids bonded together
What are the stages in translation
Start codon
Each tRNA molecule transfers it’s specific amino acid to the mRNA attached to the ribosomes
The anticodons bond to codons via weak hydrogen bonds between complementary base pairs
Peptide bonds join the amino acids together forming a polypeptide
Each tRNA then leaves the ribosome as the poly peptide is formed
Stop codon
What is alternative rna splicing
Alternative rna splicing allows the same primary transcript to form different mature mRNA transctips
The mature mRNA transcript produced depends on which exons are retained each mature transcripts will have a different combo of exons spliced together
Define mutations
A change in the DNA of an organism
Name 2 mutagenic agents
Radioactivity
Chemicals
What impacts do mutations have on
on protein or an altered protein being synthesised
Define genetic disorder
Conditions or disease Comes directly from someone’s genes
What is gene mutation (examples)
Involves a change in the DNA nucleotide sequence
DELETIOnN
INSERTION
GENE MUTATIONS
SUBSTITUTION
Describe substitution and effects
Can cause sickle cell disease
Changes 1 amino acid
Describe insertion
Causes tay sachs disease
Changes all amino acids after
Describe deletion
Can cause cystic fibrosis
Changes all amino acids after the base
What is a missense mutation
This results in one amino acid being changed for another
what is a nonsense mutation (non-stop)
This means that there is a stop codon being produced prematurely resulting in a short protein
What is a splice-site mutation
This results on some introns being retained and/or some exons not being included in the mature RNA transcript
Which point mutations lead to frameshift and missense mutations
Franeshift- insertion+deletion FDI
Missense- substitution (ms)
Describe Translocation
A section of another chromosome is added to a chromosome but its homologous partner
ABC DEF GHI JKL
ABC JKL GHI DEF
describe inversion
The section of chromosome is in reverse
ABC DEF
CBA FED
Describe deletion
Involves removing a section of a chromosome
ABC DEF
A C DEF
Describe duplication
A section of chromosomes from the homologous partner is added into chromosome
ABC DEF
ABBC DEF
What is the human genomics
The entire hereditary information encoded in DNA
What is genome sequencing
The sequence of nucleotides bases can be determined for individual genes
Why is the genome sequencing useful
This allows us to work out the sequence of amino acids for individual proteins. This allows us to detect mutations
What is bioinformatics
To compare sequence data computer and statistics analyses are required
What is a personal genome sequence
Own personal genome map or sequence
What is a personalised medicine
An individuals personal genome sequence can be used to select the most effective drugs and dosage to treat their disease
Describe pharmacogenetics
The study of how peoples genetic makeup affects their responses to drugs
What are primers
Single stranded sequences of nucleotides which are complementary to a target sequence
PCR is a technique used for what?
amplification of DNA in vitro
Define metabolism
The chemical reactions in the body
is cells that change food into energy
What is an anabolic pathway
Takes energy
Makes bonds
Synthesis
What is a catabolic pathway
Gives energy
Break bonds
Degradation
Define rate of chemical reaction
The speed at which the reaction is happening
What is the activation energy
The minimal energy required that is needed to form a product
What s a transition state
The point where there is enough energy to start the reaction but the reaction hasn’t started yet
Three facts about catalysts
Speed up chemical reaction
Doesn’t get used up in reaction
Lowers Ea
State the importance of the enzymes active site
Specific to substrate
What is meant by the term specific in relation to enzymes
Will only match a certain substrate
Describe how the enzyme becomes free to repeat the reaction again
Products leave enzymes when reaction is done e
What is meant by the term induced fit
When an enzyme binds to the substrate, the active site changes shape to fit better
State three ways that enzymes can control metabolic pathways
Inhibitors- competitive, non competitive and feedback inhibition
What is an inhibitor
A molecule that decreases the rate of an enzyme reaction
What is a competitive inhibitor
They bind to the active site and prevents the substrate from binding
How can a competitive inhibition be reversed
You can increase the concentration of substrate
Three facts about non-competative
They bind to another side of enzyme
Changes shape of active site
Can’t be reversed
Describe feedback inhibition
Feedback inhibition occurs when the en product in he metabolic pathway reaches a critical concentration
The end product the inhibits an earlier enzyme and blocks the pathway
This blockage of the pathway prevents further synthesis of end products
What is cellular respiration
Breakdown of glucose to produce atp
Name the molecules that atp is made from
Adenosine diphosphate +pi
Why is ATP so important
It provides energy for cellular processes
Why don’t humans need a vast store f ATP
It can be easily made
Three examples of processes that cell requires ATP
Mitosis
DNA replication
Active transport
Name 3 stages involved In cellular respiration
Glycolysis
Citric acid cycle
Electron transport train
What does dehydrogenase do
Takes H ions and electrons from some compounds in the energy pay off phase
List the steps involved in glycolysis
Glucose is the breakdown of glucose into pyruvate in the cytoplasm
The first part of glycolysis is an energy investment phase ATP
Describe Citric acid cycle
Occurs in the matrix of mitochondrion
Pyruvate is broken down to an acetyl group this combines with coenzyme A to from ace
What does ATP synthase do
Catalysed the formation of ATP from ADP +Pi
Describe the mitochondrion structure
Outer membrane
Matrix
Cristoe
Where does the energy come from for a repeated store of energy for repeated muscle contraction
Glucose stored as glycogen
What happens during a strenuous muscular activity
Not enough oxygen to support electron transport system
In anaerobic respiration what is the only stage that can occur
Glycolysis
When does the oxygen debt get repaid
When the exercise is complete
When atp is provided lactate back into pyruvate and glucose in the liver
What are the two types of skeletal muscle fibres
Slow and fast twitch
What is the storage in fast and slow twitch
Fast twitch fats
Slow twitch glycogen
Respiratory pathways to make atp in slow and fast twitch
Slow aerobic
Fast glycolysis
What is myoglobin made of
Protein
What is the purpose of myoglobin
To carry oxygen
Describe the energy investment phase
Involves the investment of 2 atp
The job of these atp is to provide phosphate for the phosphorylation of glucose and intermediates
Describe energy pay off phase
4 atp, net gain of 2 atp
Dehydrogenase enzyme extracts hydrogen and electrons from intermediates passing them to nad forming nadh
Describe citric acid cycle (3)
Only occur if oxygen is present
Occurs in matrix of mitochondria
Controlled by enzymes
