Topic 2 Flashcards

1
Q

How has the lungs adapted for gas exchange?

A

-Lots of alveoli, creates larger S.A to Volume for diffusion
-Alveoli and capillary endotheliums are 1 cell thick
-Good supply of blood
-Breathing in and out, refresh air -> maintain concentration gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Structure of a phospholipid + its properties

A

-Phosphate head, attracts water
-2x Fatty Acid Tails, repels water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is faciliated diffusion?

A

-Diffusion for larger and charged particles
-Across a membrane, down the concentration gradient
-Passive process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Explain active transport

A

-Movement of substances against a concentration gradient
-A molecule attaches to the carrier protein
-It changes shape and moves the molecule across a membrane, releasing it
-Uses ATP as energy, produced by respiration
-ATP is hydrolysed for use

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Explain endocytosis

A

-A cell membrane can surround substance
-Membrane pinches off in the inner, forming a vesicle
-Uses ATP for energy, accessed by hydrolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Explain exocytosis

A

-Vesicles containing substance pinch off sacks of the golgi apparatus to the cell membrane
-Vesicle fuses into the membrane, releasing contents out of the C.M

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Structure of a protein

A

-Made from mono/polymers of amino acids
-Which join together through a condensation reaction
-Forming peptide bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Explain globular protein structure

A

-Globular proteins are round, compact
-Made of multiple polypeptide chains
-Coiled up, hydrophillic parts on outside and hydrophobic on inside
-Protein is soluble, easy for transportation
-E.g Haemoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Explain fibrous 3d protein structure

A

-Fibrous proteins are made of long, insoluble polypeptide chains
-Polypeptide chains held together by many bonds (disulfide, H)
-Strong and long, can be found in supportive tissues
-E.g Collagen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain enzymes

A

-Is a biological catalyst
-Is a protein
-Have an active site, which has specific shape where substrate molecules bind to
-Lower the activation energy of a reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Explain RNA

A

-RNA is similar to DNA
-RNA transfers genetic information from DNA to ribosomes
-Its nucleotide has a ribose sugar
-Are polymers of mononucleotides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Explain nucleotides

A

-Pentose Sugar (5C Sugar)
-Nitrogen-containing organic base
-Phosphate group
-Make up DNA and RNA
-Phosphodiester bonding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Explain DNA

A

-DNA stores genetic information
-Are polymers of mononucleotides
-Its nucleotide has a deoxyribose sugar
-TAGC bases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Explain mRNA

A

-Messenger RNA is made in the nucleus, during transcription
-3 adjacent bases = codon
-Carries genetic code from DNA in nucleus to cytoplasm, for translation into a protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Explain tRNA

A

-Transfer RNA is in the cytoplasm
-Has amino acid binding site
-Has a sequence of 3 bases, a complementary anticodon
-Carries amino acids to ribosomes during translation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Explain Non-Overlapping and Degenerate code

A

-N.O: each base triplet (codon) is read in sequence, no codons share bases
-Dg: amino acids are able to be coded for by more than one codon

17
Q

Explain transcription

A

-RNA polymerase attaches to DNA double helix at beginning
-DNA Helicase leads to H bonds breaking, strands seperate, DNA Helix unwinds
-One strand is used as a template
-RNA polymerase lines up free floating RNA nucleotides to complementary base pair with the template
-RNA polymerase joins the original strands together, leaving the new mRNA strand
-H Bonds reform once RNA polymerase has passed
-Stops at a stop codon
-mRNA moves out through a nuclear pore, to a ribosome in the cytoplasm for translation

18
Q

Explain translation

A

-mRNA attaches to ribosome, and tRNA, in cytoplasm
-tRNA with complementary anticodon pairs to the mRNA
-A 2nd tRNA does the same, and this repeats
-Amino acids on the tRNA molecule are joined via a peptide bond, prior tRNA leaves
-Polypeptide moves away from the ribosome when a stop codon is reached

19
Q

Explain semi-conservative replication

A

-DNA helicase breaks H bonds between bases on the strands, unwinding it
-Both strands act as a template strand, free floating DNA nucleotides begin to complementary base pair.
-Condensation reactions occur, joining the nucleotides of strands together catalysed by DNA polymerase
-Hydrogen bonds form between bases
-Ultimately two DNA molecules have formed, both have an original and new strand

20
Q

Name the 5 types of mutation

A

-Substituion
-Deletion
-Insertion
-Duplication
-Inversion

21
Q

What does a mutation lead to?

A

-Order of DNA bases change
-This changes order of amino acids
-Changes primary structure, and it’s final 3D shape, protein may not function
-Mutation of a gene can lead to a genetic disorder e.g CF

22
Q

Explain Cystic Fibrosis and its cause

A

-Inherited disorder affecting respiratory, digestive and reproductive systems
-Caused by recessive allele (f)
-Person gets it if they are homozygous with the allele (ff)
-Caused by a mutation in gene for CFTR protein

23
Q

Explain effects of cystic fibrosis

A

-Caused by a mutation in gene for CFTR protein
-CFTR is a channel protein which transports Cl ions out of cells into mucus
-Causes water to move into mucus via osmosis, making it watery

-Mutant CFTR makes it less efficient at Cl movement so less water moves out and into mucus via osmosis
-Mucus becomes thick and sticky, affecting body systems

24
Q

State 3 uses of genetic screening

A

-Identification of carriers
–>Done before having children, life insurance/companies use data (genetic discrimation)
-Preimplanation Genetic Diagnosis
-Prenatal Testing

25
Q

Explain preimplantation genetic diagnosis

A

-Carried out on embryos before implantation, to find genetic disorders
-Reduces chances of embryo with a genetic disorder
-Avoids abortion
-Social/ethical issues (designer babies)

26
Q

Explain prenatal testing

A

-Screening unborn babies for genetic disorders
-Amniocentesis
-Chorionic Villus Sampling

27
Q

Explain amniocentesis

A

-Carried out at 15-20 weeks
-Using fine needle into abdomen, obtain amniotic fluid (surrounds the fetus)
-This fluid contains fetal cells for DNA analysis
-1% risk of miscarriage
-Rapid test, only looks for common disorders is 3-4 days
-Normal test, detailed is 2+ weeks

28
Q

Explain Chorionic Villus Sampling

A

-Carried out at 11-14 weeks
-Early in pregnancy, decision able to be made earlier
-Sample is taken from chorionic villi, part of fetus connected to mother
-Fetal cells taken for DNA analysis
-Done through abdomen using fine needle
-Done through vagina using catheter
-2% risk of miscarriage
-Rapid test, only looks for common disorders is 3-4 days
-Normal test, detailed is 2+ weeks