Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology > Topic 2~ Genes And Health > Flashcards

Topic 2~ Genes And Health Flashcards

1
Q

What type of cell produces mucus

A

Goblet cells

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

What are the properties of gas exchange surfaces

A
  • large surface area : volume
  • good blood supply
  • thin walls
  • concentration gradient (greater the better)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Ficks law

A

Rate of diffusion is directly proportional to

SA x difference in conc / thickness

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

Structure of an amino acid

A

Central carbon is bonded to an anime group (NH2) opposite a carboxylic acid group (COOH) and a hydrogen (H) opposite an R group

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

What is the primary structure of a protein

A

The sequence of amino acids in a polypeptide chains

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

Formation of a dipeptide

A

2 amino acids join by peptide bonds by a condensation reaction

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

What is the secondary structure of a protein

A

Polypeptide chains twist or fold to form a-helix or b-pleated sheets with hydrogen bonding between C=O and NH

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

What is the tertiary structure of a protein

A

Polypeptide chain bends and folds further into a precise 3-dimensional shape. Ionic bonds and disulphide bridges form

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

What is the quaternary structure of a protein

A

Multiple polypeptide chains held together

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

What are conjugated proteins

A

Proteins that have another chemical group associated with their polypeptide chain
Like haemoglobin is associated with iron

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

What are globular proteins + examples

A

The polypeptide chain is folded into compact spherical shape
Roles in binding to other substances

Haemoglobin
Enzymes
Antibodies

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

What are fibrous proteins + examples

A

Do not fold into a sphere but instead remain as long chains. Have cross linkage between chains for strength
Important structural molecules

Keratin
Collagen
Tendons

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

Structure of haemoglobin

A

Globular protein
conjugated protein
Made up of 4 polypeptide chains
Each associated with iron haem group

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

Structure of collagen

A

Fibrous protein
Made up of 3 polypeptide chains wind around each other forming triple helix (rope like)
Held by hydrogen bonds
Each stand cross links to other stands
Strands are staggered to avoid weak points

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

What are peripheral proteins

A

Proteins that are attached on the outside surface of the cell membrane

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

What are integral proteins

A

Proteins that are fully embedded within the phospholipid bilayer

They have regions of polar hydrophilic amino acids at the ends and non polar hydrophobic amino acids in the middle portion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How can the phospholipid bilayer become more fluid

A

With a greater ratio of unsaturated to saturated fatty acids

The kinks prevent them from packing closely together so more movement is possible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is facilitated diffusion

A

Diffusion across the membrane with the aid of proteins for polar molecules and ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are channel proteins

A

They are proteins that span the membrane and allow polar molecules and ions to diffuse through

Each type has a specific shape that permits the passage of a particular ion or molecule

Some are opened and closed depending on the presence or absence of a signal, like a hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are carrier proteins

A

Proteins in the membrane that transport polar molecules or ions.

The ion or molecule bonds onto a specific site on the protein causing it to change shape. As a result the ion or molecule crosses the membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why is diffusion sometimes called passive transport

A

Because no metabolic energy is needed for the transport - it’s driven by the concentration gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Definition of osmosis

A

The net movement of water molecules from a solution with high concentration of water (low solute conc) to a low concentration of water (high solute conc) through a partially permeable membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Definition of isotonic

A

Equilibrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Describe the process of active transport

A

Movement of substances from low to high concentration
Requires carrier proteins and ATP
- Substance binds to the carrier protein
- 1 phosphate group is removed from ATP by hydrolysis forming ADP and inorganic phosphate
- phosphate gets hydrated, lots of energy released as bonds form between water and phosphate changing shape of carrier protein
- substance released on other side

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is exocytosis
Release of substances from the cell as vesicles fuse with the cell membrane releasing the contents
26
What is endocytosis
Substances are taken into cell by creation of a vehicle from the cell surface membrane - part of the membrane engulfs the substance
27
What happens when there is too much water in mucus of lungs
- sodium is actively pumped out of cells into tissue fluid, reducing sodium conc in the cell - sodium then diffuses out of mucus and into cells - chloride diffuses down electrical gradient - water is drawn out of the cells by osmosis due to high salt conc in tissue fluid - water is then drawn out of the mucus by osmosis
28
What happens when there is too little water in the mucus of the lungs
- chloride is pumped into the cell from tissue fluid - chloride diffuses through the open CFTR channel in mucus - sodium diffuses down electrical gradient into the mucus - increased salt conc in mucus draws water out of the cell by osmosis - water is drawn into the cell from the tissue fluid by osmosis
29
Why can’t Cystic fibrosis lungs regulate water in the mucus
- the CFTR protein is missing or not working - so chloride ions cannot be transported into the mucus when it’s too sticky - sodium channels are still open allowing more sodium ions to diffuses out of the mucus - more water is drawn out of mucus - even stickier
30
Describe the lock and key theory
- substrate molecule has a complementary shape to the active site - form temporary bonds with the active site to produce enzyme-substrate complex - products are then released leaving enzyme unchanged - each enzyme will catalyses one specific reaction as only one shape of substrate fits precisely to active site
31
Describe the induced fit theory
- active site is flexible - when the substrate enters the active site, enzyme changes shape slightly to fit mire closely around substrate - only specifically shaped substrate will induce the correct change in shape of enzymes active site
32
How do enzymes reduce the activation energy
Electrically charged groups on surface of active site and substrate interact Attraction of oppositely charged groups distorts the shape of the substrate assisting in breaking or forming bonds
33
Definition of metabolism
The sum of all the enzyme catalysed reactions occurring within an organism
34
What are intercellular enzymes
enzymes that catalyse reactions inside cells
35
What are extracellular enzymes
Enzymes that catalyse reactions outside cells
36
What is a gene
Sequence of bases on a DNA molecule that codes for a sequence of amino acids
37
What is the genome
All the genes in an individual
38
What are the monomers of DNA
Nucleotides
39
What’s the structure of a nucleotide
Deoxyribose sugar, a phosphate group and an organic nitrogenous base linked by condensation reactions
40
How do nucleotides join together
Condensation reactions between the sugar and phosphate forming a phosphodiester bond
41
Why do the bases pair up
- A, G have 2 ring structure - T, C have 1 ring structure Each ‘ring’ of DNA has 3 rings - shape and chemical structure dictates how many hydrogen bonds each one can form, determining the pairing
42
What is the difference between DNA and RNA
- RNA is single stranded - RNA is made of RNA nucleotides (contain ribose sugar instead of deoxyribose) - RNA has uracil instead of thymine
43
Describe the process of transcription
- DNA unwinds by breaking hydrogen bonds - template strand is transcribed using free RNA nucleotides, DNA polymerase and complementary base pairing to form an mRNA molecule - mRNA leaves nucleus through pore in the nuclear envelope and DNA ‘zips up’
44
Which strand is the antisense strand
Template strand
45
Describe the nature of the genetic code
- code carried by DNA in triplets - non-overlapping (each base read once) - degenerate (several triplets code for same amino acid)
46
Describe the process of translation
- mRNA attaches to a ribosome - tRNA anticodon hydrogen bonds to complementary codon on mRNA for a particular amino acid - ribosome holds it all in place while peptide bond forms between amino acids by condensation reactions
47
Where are ribosomes found
- free in cytoplasm | - attached to endoplasmic reticulum
48
How do stop codons work
There are no tRNA molecules with complementary anticodons to stop codon sequences so no amino acid can be transferred. The polypeptide chain stops growing and detached from the ribosome
49
Compare DNA replication and transcription
- both create new molecule of nucleic acids - both make copies of DNA - transcription copies DNA into RNA while replication makes another DNA - transcription is for gene expression while replication is for cell division - transcription uses RNA nucleotides and replication uses DNA nucleotides - transcription unwinds part of DNA but replication unwinds entire DNA
50
Describe DNA replication
- hydrogen bonds between bases break making DNA unzip - DNA nucleotides pair up with complementary bases - DNA polymerase links adjacent nucleotides - 2 identical daughter strands created
51
Describe Meselson and Stahls experiment for DNA replication
- grew Bacteria in a medium with heavy isotope of nitrogen - moved bacteria into medium with lighter nitrogen - extracted and centrifuged DNA - after 1 replication only 1 band formed showing medium dentistry (heavy + light) - after 2 replications 2 bands formed showing medium density and light density - proves semi conservative replication
52
Definition of locus
The position of a gene on a chromosome
53
Definition of homologous chromosomes
Chromosome pairs inherited from each parent
54
Definition of allele
Alternative forms of the same gene
55
Definition of genotype
Alleles a person has
56
Definition of homozygous genotype
Identical alleles
57
Definition of heterozygous genotype
Different alleles
58
Definition of phenotype
Characteristics of the organism caused by the genotype
59
Definition of monohybrid inheritance
Characteristic controlled by only one gene
60
Definition of incomplete dominance
Neither allele is dominant so heterozygotes have an intermediate phenotype
61
How can genetic screening be used
- to confirm diagnosis - to identify carriers - for testing embryos
62
What is amniocentesis
Common method of prenatal testing Involves inserting a needle into amniotic fluid to collect fetal cells that have fallen off the placenta
63
What is chorionic villus sampling
Method of prenatal testing Small sample of placental tissue is removed through abdomen wall or vagina
64
What are the implications of prenatal genetic screening
- both procedures present risk of miscarriage
65
What is non-invasive prenatal diagnosis
Analysing DNA fragments in mothers blood plasma during pregnancy
66
What is pre-implantation genetic diagnosis (PGD)
When a couple has family history of a serious genetic condition or already have a child with the condition they undergo IVF to create embryos that can be tested before transfer to the uterus

Biology (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions