DLISC1 WK1-5 Flashcards
(70 cards)
1
Q
what are the 7 characteristics of a living organism?
A
- ordered complexity
- cellular organisation
- energy utilisation
- growth, development, and reproduction
- homeostasis
- sensitivity
- evolutinary adaptation
2
Q
Three key reasons why visuses can evolve
A
- lack of proofreading ability of viral RNA polymerases
- short generation times
- genetic reassortment
3
Q
what is a virus
A
- a non-cellular and infectious ‘entities’
- use the host cells energy and biosynthetic machinery to make copies of itsself
- does not fit the defintion os living things (7)
4
Q
structure of viruses
A
- alternate between 2 states: intracellular (in host) and extracellular (virion)
- basic structure: nucleic acid core, protein coat surrounding nucleic acid core (capsid) and no cytoplasm
- most DNA viruses are ds
- all RNA viruses are ss
5
Q
explain the steps of viral replication
A
- attachemnt to host
- entry - viruses penetrate to cell membrane, uncoating of genome, releasing nucleic acid into cell
- synthesis - viral ‘genes’ expresssed and replicated using host machinery
- assembly - nucleic acid packaged into virions through self-assembly
- release - of progeny virions (host cell may be destroyed in the process)
6
Q
what is protein trafficking?
A
process by which proteins are transported from their sites of synthesis to where they are needed
7
Q
Describe the process of protein trafficking
A
- Protein synthesis beings when a gene on DNA produces messenger RNA (mRNA), the temple from protein synthesis
- The mRNA leaves the nucleus and attaches to a free ribosome in the cytoplasm, or a fixed ribosomes on the RER
- Proteins constructed on free ribosomes are released into the cytosol for use within the cell
- Protein synthesis on fixed ribosomes occurs at the RER. The newly synthesised protein folds into its 3-dimensional shape
- The proteins are then modified within the ER. Regions of the ER then bud off forming transport vesicles containing modified proteins and glycoproteins
- The transport vesicles carry the proteins and glycoproteins generated in the ER toward the Golgi apparatus. The transport vesicles then fuse to create the forming cis face (“receiving side”) of the Golgi apparatus
- Multiple transport vesicle combine to form cisternae on the cis face. Further protein and glycoprotein modification and packaging occur as the cisternae move toward the maturing (trans) face. Small transport vesicles return resident Golgi proteins to the forming cis face re use.
- The maturing trans face (“shipping side”) generates vesicles that carry modified proteins away from the Golgi apparatus. One type of vesicle becomes a lysosome, which contains digestive enzymes
- Two other types of vesicles proceed to the plasma membrane: secretory and membrane renewal. Secretory vesicles fuse with the plasma membrane and empty their products outside the cell by exocytosis. Membrane renewal vesicles add new lipids and proteins to the plasma membrane
8
Q
what is the mitochondria?
A
tubular organelles surrounded by a double membrane
9
Q
what is the cytoskeleton?
A
cytoplasm or eukaryotes contains network or protein fibres, constantly assembling and disassembling, it support the cell shape.
10
Q
what are the 4 main componenets in plasma membrane?
A
- cholestrol
- phospholipid bilayer
- proteins
- carbohydrates
11
Q
function of cell/plasma membrane
A
- controls the movement of substacnes in and out of the cell
- semipermeable membrane that surrounds the cytoplasm
- protects the integrity of the cell by allowing certain substances into the cell whilst keeping others out
- support the cell by maintaining shape
12
Q
explain glycoproteins (type of carbohydrate)
A
Glycoproteins are membrane carbohydrates linked to proteins. These protein chains account for the majority of protein chains found on the cell membrane. These compounds also help with cell-to-cell recognition.
13
Q
explain glycolipids (type of carbohydrate)
A
Glycolipids are membrane carbohydrates linked to lipids. They account for 5% of the lipids in the cell membrane. These carbohydrate chains help in cell-to-cell recognition.
14
Q
What is osmosis?
A
It is a type of diffusion in which water moves across a plasma membrane or any other selectively permeable membrane from a region of higher water concentration to a region of lower water concentration.
15
Q
osmosis - hypertonic
A
concentration of solutes is higher on the outside relative to the inside. if a cell is in a hypertonic environment, water will move out of the cell
16
Q
osmosis - isotonic
A
inside and outside have the same concentration so there is no water flow
17
Q
osmosis - hypotonic
A
concentration of solutes is lower outside than inside the cell, so water will move into the cell
18
Q
What is solute?
A
a substance dissolved in another substance, usually the component of a solution present in the lesser amount
19
Q
what is solvent?
A
a usually liquid substance capable of dissolving or dispersing one or more other substances
20
Q
explain passive transport
A
- Does not require energy, and uses a concentration gradient (moves from higher to lower concentration)
- there is a simple diffusion and facilitated diffusion which occurs until the concentration is equal on both sides
21
Q
what is simple diffusion?
A
molecules that can freely pass through the membrane are controlled by the concentration gradient
22
Q
what is facilitated diffusion?
A
aided by a carrier protein and controlled by a concentration gradient
23
Q
what is active transport?
A
- Does require energy
- Goes against a concentration gradient (can move things from a lower concentration to a higher concentration)
24
Q
explain one type of active transport
A
coupled trasnport
some molecules move agaisnt their concentration gradient by using the energy stored in a gradient of a different molecule (indirect use of ATP)
25
transport using a vesicle
When the cell needs to transport larger things they can use vesicles to transport things in and out of the cell
- Exocytosis: moving things out of the cell using a vesicle
- Endocytosis: moving things into the cell using vesicles
26
Who deduced the double helix structure and what year?
James Watson and Francis Crick in 1953
27
Eukaryotic cell division is divided in phases, brifely describe
Interphase = G1, S, G2 (between cell divisions)
M Phase = mitosis and cytokinesis (dividing phases)
28
genetic shuffling of Meiosis 1
In addition to a new combination of chromosomes resulting from fertilisation, there are also events in Meiosis 1 that shuffle the genes
1. Crossing over in prophase 1
2. Independent assortment in metaphase 1
29
levels of organism (more complex)
atom
molecule
macromolecule
organelle
cell
tissue
organ
organ system
organism
30
what is the central dogma?
1958 - crick coined the phrase 'central dogma' to refer to the flow of genetic infromation from DNA to protein
31
what is a genotype?
- the specific allele composition of a cell
- the complete set of genes inherited by an individual organism
- inherited from parents
- identical twins share the same genoype
32
what is a phenotype?
- the detectable outward manifestations of a specific genotype
- describes all aspects of an indivdual organisms morphology
- heritable component, but influenced by the environment
- no tow organisms share the same phenotype
33
what are mutations?
- changes in nucleotided sequence of DNA
- may occur in somatic cells and gametes
34
name two genetic disorderes with medilian phenotypes?
- hemophilia
- muscular dystrophy (duchenne)
35
describe hemoplilia
symptom: blood fails to clot
defect: defective blood clotting factor VIII
dominant/recessive: x-linked recessive
36
describe muscular dystrophy (Duchenne)
symptom: muscle waste away
defect: degradation of myelin coating nerves stimulating muscles
dominant/recessive: x-linked recessive
37
types of mutations
chromosome mutation
gene mutations
38
chromosome mutations
- the mutation of the chromosomal segments of the DNA strands
- five types exist: deletion, inversion, duplication, translocation and nondisjunction
39
gene mutations
- refer to base change in the nucelotide sequence of a gene intragentic additions, deletions or rearrangements that disrupt normal gene function
- types: point mutations (includes substitutions, insertions and deletions) and frameshift
40
genetic disorders
- many hereditary disorders are caused by recessive, defective alleles
- estimated that people carry 3-5 such alleles
- each paretns must carry 1 recessive allele. offspring must inherit the defective allele from both paretns and ge thte disease
41
structure of prokaryotic cell
cytoplasm
plasmid
flagellum
plasma embrane
cell wall
capsule
nucelotide
ribosomes
pili
42
prokaryotic cells
- single-celled organism which lacks a nucleus and other membrane-bound organelles
- shape and size can be one of three determined by cell wall: rods, spherical or oval, long and helical
43
eukaryotic cells
- more complex then prokaryotic
- DNA housed in nucleus
- supported by cytoskeleton internal protein scaffold
44
structure of eukaryotic cells
peroxisome
mitochondria
vacuole
golgi apparatus
nucleus
ribosomes
cytoplasm
lysosome
cell membrane/plasma membrane
nucleus
cytoskeleton
endoplasmic reticulum
45
eukaryotic cell division/cycle
1. G1 (gap/growth phase 1) - growth and preparation of DNA synthesis
2. S (synthesis) - DNA replication
3. G2 (gap/growth phase 2) - growth and preparation for mitosis; oprganelles replicate and microtubles form spindle
4. mitosis - serperation of replicated chromosomes, subdivided into 5 phases
5. cytokenesis - cytoplasm divides leading to seperation of 2 daughter cells
46
what is mitosis?
- division of somatic cells in eukaryotic organisms
- a single cell divides into 2 identical daughter cells
- daughter cells have same number of chromosomes as does parents cells
- 5 phases (PMAT)
1. prophase
2. prometaphase
3. metaphase
4. anaphase
5. telophase
47
what is meiosis?
is a type of cell division that occurs in sexually reproducing organisms, resutling in the formation of four unique daughter cells, each with half the number of chromosomes of the original cell. process is crucial for reproduction as it produces games (sperm and egg cells)
48
what are the 4 primary tissue types?
epithelial
connective
muscle
nerve
49
epithelial tissues
- can arise form all primary germ layers
- function: protection, absorption, secretion and filtration
- can be simple (1 layer thick) or stratified (2+ layers thick)
50
connective tissues
- connect and support to other tisseu types
- arise from mesoderm
- two classes: connective tissues proper - loose or dense, special connective tissues
51
muscle tissues
- initial force: converts chemcial energy to mechanical energy
- can be one of three types: smooth, skeletal nad cardiac
52
trait inheritance
sexual reproduction invovles...
Mendel’s 5 element model of inheritance
1.Parents transmit discrete factors (what we now call genes)
2.Each individual receives one copy of a gene from each parent
3.Not all copies of a gene are identical
4.Alleles remain discrete – no blending/intermediate phenotypes
5.Presence of allele does not guarantee expression
53
make a statement about protein synthesis:
transcrption is the production of messenger RNA (mRNA) from DNA
54
what type of molecule is transported via simple diffusion?
lipid-soluble molecules
55
in a single sodium-potassium pump cycle, ATP is used with the result of...
3 sodium ions move into the cell, 2 potassium ions leave the cell
56
mitochondria are primarily involved in...
energy release/capture
57
the nucleus contains?
nucleic acids
58
classification of epithelial tissue is based one?
shape and number of layers of epithelial cells
59
which term describes the effect of diseases on our bodies?
pathological physiology
60
which organ systems are involved in homeostasis regulation of body temperature?
integumentary, muscular, cardiovascular and nervous
61
the regulation of blood clotting involves?
positive feedback
62
how do you determine the phenotype of an organism?
look at the organism
63
what is an oncogene?
it is a mutated gene that has the potential to cause cancer
64
what is a wild-type?
organism with the normal form
65
what is a mutant?
individaul organisms having some altered form of a normal property
66
normal human eggs have?
22 autosomes and one X chromosome
67
what type of cells does mitosis create?
diploid
68
what does a karyotype description of 46 XY mean?
a normal human karyotype
69
which requires energy in the form of ATP?
active trasport
70
what is the function of the cytoskeleton?
strength, support and movement of cellular structures and materials
