Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology 3 > Cr 5 - Molecular Biology > Flashcards

Cr 5 - Molecular Biology Flashcards

1
Q

2 types of living things

A

Non-Cellular & Cellular

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

Non cellular

A

Prions & viruses

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

Cellular

A

Prokaryotic & Eukaryotic

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

Necessary features of an organism

A

Movement
Respiration
Sensing stimuli
Growth
Reproduction
Excretion
Nutrition

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

Prokaryotes

A

Definition: Organism whose cells lack a nucleus and other organelles
Features:
- Nucleoid region
- No membrane bound organelles
- Generally smaller
- Smaller ribosomes
- Naked DNA
- Plasmid - small, circular double-stranded DNA molecule

Examples: Bacteria, Archaea

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

Eukaryotes

A

Definition: Organisms whose cells have a membrane bound nucleus.
Features:
- nucleus
- membrane bounds organelles
- generally larger
- larger ribosomes
- DNA associated with proteins
- no plasmid

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

Plant Cells

A

Features:
- Cell wall present
- chloroplasts present
- large central vacuole
- centrioles may be absent
- generally larger

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

Animal Cells

A
  • Cell wall absent
  • chloroplasts absent
  • vacuoles small or absent
  • centrioles present
  • generally smaller
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

ORGANELLES - Mitochondria

A

Definitions:
Site of aerobic respiration
Site of ATP production (ATP is an energy source “currency” of the cells and is Adenosine Triphosphate)

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

ORGANELLES - Smooth & Rough ER.

A

Smooth ER:
Site of lipid and carbohydrate synthesis

Rough ER:
Site of protein synthesis

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

ORGANELLES - Nucleus

A

The nucleus contains the DNA and controls the activities of the cell

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

ORGANELLES - Golgi body (apparatus)

A

Site of processing / packaging of protein and lipid molecules, especially proteins to be exported from the cell.

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

ORGANELLES - Ribosomes

A

Site of protein synthesis
- Synthesise proteins in cells by linking amino acids together in the order specified by messenger RNA.

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

ORGANELLES - Cell Membrane

A

Controls entry and exit of substances in and out of the cell

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

ORGANELLES - Cell Wall

A

Provides structure and rigidity (plant cells only)

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

ORGANELLES - chloroplasts

A

Site of photosynthesis (plant cells only)

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

ORGANELLES - Vacuole

A

Storage of nutrients/water

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

Metabolism

A

The sum of all chemical reactions that occur in an organism.

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

ENZYMES

A

Function: Are able to speed up a reaction without being chemically altered.
Features:
- Are specific to particular substrates
- Are reversible
- Are only needed in small amounts
- Usually end in ‘ase’
- Are globular (spherical proteins)
- Have an active site to which the substrate binds
Substrate + Enzyme = Product + Enzyme

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

Substrate + Enzyme = ?

A

Product + Enzyme

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

ENZYMES - Catabolism

A

Substances are broken down

22
Q

ENZYMES - Anabolism

A

Substances are built up

23
Q

FACTORS EFFECTING ENZYME ACTIVITY - Temperature

A

*See physical card for reference graph

  1. Low temp = low kinetic energy. Less collisions, less enzyme-substrate complexes, decreased enzyme activity
  2. Increased temperatures = Increased kinetic energy. More collisions, more enzyme-substrate complexes, increased enzyme activity.
  3. Optimum temperature (Turning point)
  4. At too high temperatures, the enzyme denatures. i.e. the bonds of the active site break. This causes the shape of the active site to change so that it can no longer bind to substrates.
    Because they are made of proteins (amino acids vibrate too vigorously, breaking the hydrogen bonds between them) the enzymes denature (break down).
24
Q

FACTORS EFFECTING ENZYME ACTIVITY - pH

A

*See physical card for reference graph
1. Optimum pH (turning point)

  1. pH is too acidic: enzyme denatures due to an abundance of hydrogen ions which interact with the amino acids, changing the shape of the active site
  2. pH is too alkaline: enzyme denatures
    Optimal pH depends on where the enzyme works in the body. i.e. pepsin works in the stomach (acidic)

https://www.youtube.com/watch?v=IoDEjeRZ0xE

25
Q

FACTORS EFFECTING ENZYME ACTIVITY - Substrate concentration

A

As substrate concentration increases, enzyme activity will also increase.
- Low substrate concentration = free active sites
- Saturated substrate concentration = no active sites. i.e. they are all filled with substrate, causing the enzyme activity to plateau flat.
Graph roughly looks like this.
/────
No matter how much more substrate is added, there are no free active sites to increase the rate during the flat concentrations.
https://www.youtube.com/watch?v=5bIOwLlT3IA

26
Q

INHIBITION - competitive

A

-Inhibitor is chemically similar to substrate
- Inhibitor binds to the active site (preventing substrate from binding to active site), therefore decreasing the number of enzyme-substrate complexes.
- However, an increased concentration of substrate, the effect of the inhibitor is reduced.
https://www.youtube.com/watch?v=jJUoQMLMV2E

27
Q

INHIBITION - non-competitive

A
  • Inhibitor is not chemically similar to substrate
  • It binds to the allosteric site of the enzyme (not active site)
  • Induces a conformational change as it changes the shape of the active site
  • Substrate cannot bind which results in decreased enzyme activity.
    https://www.youtube.com/watch?v=jJUoQMLMV2E
28
Q

INHIBITION - information

A

Enzyme inhibitors can be beneficial in controlling biochemical pathways or they can be poisonous. Inhibitors can be both irreversible and reversible.

29
Q

4 Biomolecules

A
  • Proteins
  • Lipids
  • Carbohydrates
  • Nucleic Acids
30
Q

Cofactors (and coenzymes)

A
  • Non-protein components of an enzyme.
  • If the cofactor is organic, it is called a co-enzyme.
  • Coenzymes are often vitamins, inorganic cofactors can be minerals.
  • Cofactors & coenzymes may be permanent or temporary
  • Cofactors & coenzymes often sit in the active site.
31
Q

Apoenzyme

A

An inactive enzyme without the cofactor

32
Q

Holoenzyme

A

Complete enzyme with cofactor

33
Q

DNA (features)

A
  • Double stranded
  • 4 nitrogenous bases: adenine, thymine, cytosine, guanine
  • Contains deoxyribose (sugar)
34
Q

RNA (features)

A
  • Single Stranded
  • 4 nitrogenous bases
  • Adenine, Cytosine, Guanine and Uracil
  • Contains ribose (sugar)
35
Q

Process of protein s___

A

Synthesis

36
Q

DNA to mRNA

A

Transcription

37
Q

mRNA to protein

A

Translation

38
Q

Step one

A

DNA in the nucleus (not doing anything)

39
Q

Step 2

A

DNA unwinds due to RNA polymerase, leaving exposed bases

40
Q

Step 3

A

Free mRNA nucleotides form base pairs with ONE of the exposed strands

41
Q

Step 4

A

The mRNA detaches, the DNA rewinds

42
Q

Step 5

A

The pre-mRNA is spliced: the introns (intervening sequences) are removed and the exons (expressed sequences) are stitched together to form mature mRNA

43
Q

Introns

A

Intervening Sequences: Sections of mRNA that do not code for a protein (are removed)

44
Q

Exons

A

Expressed Sequences: Sections of mRNA that do code for a protein (are kept)

45
Q

Step 6

A

The mature mRNA exits the nucleus through a nuclear pore. In the cytoplasm, it binds to a ribosome.

46
Q

What is a ribosome made of

A

rRNA (ribosomal RNA)

47
Q

Step 7

A

The mRNA binds to the small subunit of the ribosome

48
Q

Step 8

A

In the cytoplasm, there are transfer RNA (tRNA) molecules which carry an amino acid at one end and have a corresponding anticodon.
Simplified: tRNA carries an amino acid at one end and a codon at the other, and the tRNA’s codon corresponds with the amino acid that a mRNA codon wants.
Example: If a codon in a chain was CUA, and its amino acid was amino acid X, a tRNA molecule would come and would have a codon of GAU and would have amino acid X on the other end.

49
Q

Step 9

A

The tRNA with the amino acid that corresponds to the start codon will bind to the mRNA. A second tRNA binds to the second codon and a peptide bond forms between the two amino acids.

50
Q
A

Biology 3 (6 decks)

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