Molecular Composition of Cells Flashcards

1
Q

What are carbohydrates? What do they do?

A

Carbohydrates include simple sugars as well as polysaccharides.
They are the major source of nutrients in the cell and are a major structural molecule that plays a role in signalling and cell recognition.

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

What are monosaccharides?

A

Simple sugars with the basic formula (CH2O)n

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

What are triose sugars?

A

Breakdown products of glucose from glycolysis and a precursor of pyruvate

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

What is ribose?

A

A pentose sugar important for forming the backbone of RNA molecules

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

What is glucose?

A

A hexose sugar which functions as the principle source of the cell’s energy

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

What is a disaccharide?

A

2 monosaccharides linked together by glycosidic bonds (lactose or sucrose)

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

What is an oligosaccharide?

A

3 or more monosaccharides linked together by glycosidic bonds

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

What is a polysaccharide?

A

100s to 1000s of monosaccharides linked together by glycosidic bonds (glycogen or starch)

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

What is glycogen? What is its function?

A

Branched alpha glucose polymer.

Major storage polysaccharide in animal cells

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

What is starch? What is its function?

A

Branched or unbranched alpha glucose polymer.

Major storage polysaccharide in plants.

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

What is cellulose? What is its function?

A

Unbranched polymer of beta glucose molecules.

Structural component component of plant cell walls.

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

What is chitin? What is its function?

A

Unbranched polymer of beta glucose molecules.

Structural component of fungal cell walls and the exoskeletons of crabs and insects.

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

What is the function of lipids? What are they a major component of?

A

Lipids provide energy storage and play a role in cell signalling and cell recognition.
Major component of cell membranes.

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

What is the structure of fatty acids?

A

Fatty acids consist of long hydrocarbon chains. The bonds between carbon and hydrogen are non-polar, resulting in fatty acids being hydrophobic.

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

What is the structure of triacyglycerols? What is their purpose?

A

Consist of three fatty acids linked to a glycerol molecule. Not soluble in water.
Store fatty acids.

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

What are phospholipids? What do they do?

A

Consist of two fatty acids joined to a polar head group, and a hydrophobic tail.
Amphipathic. Principal components of cell membranes.

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

What is the function of glycolipids?

A

Help facilitate cell stability and cellular recognition.

18
Q

What are steroid hormones? What do they do?

A

Steroid hormones are derivatives of cholesterol and act as signalling molecules both with and between cells.

19
Q

What is deoxyribonucleic acid? Where is it located?

A

DNA is the genetic molecule of the cell and is located in the nucleus of eukaryote cells.

20
Q

What does messenger RNA do?

A

Carries information from DNA to the ribosomes.

21
Q

What are ribosomal and transfer RNA involved in?

A

Protein synthesis.

22
Q

What is the structure of DNA and RNA?

A

Polymers of nucleotides, which consist of purine and pyrimidine bases linked to phosphorylated sugars.

23
Q

What is the function of purine and pyrimidine bases?

A

Provide the identity to nucleotides of DNA and RNA that are critical for base-pairing and the genetic code.

24
Q

What are nucleosides?

A

A nitrogenous base linked to the ribose or deoxyribose sugar.

25
Q

What are nucleotides?

A

Contain the phosphate group and are the basic building blocks of RNA and DNA

26
Q

Where do phosphodiester bonds form?

A

Between the 5’ phosphate of one nucleotide and the 3’ hydroxyl on the sugar of another.

27
Q

What joins amino acids together?

A

Peptide bonds

28
Q

What are polypeptides?

A

Linear chains of amino acids

29
Q

What is the primary protein structure?

A

The linear sequence of amino acids in the protein’s polypeptide chain.

30
Q

What is the secondary protein structure? What are 2 types of secondary structures?

A

The regular arrangement of amino acids within localized regions of the polypeptide.
An alpha helix and a beta sheet are two types of secondary structures/

31
Q

What is the tertiary structure of proteins?

A

The third level which consists of the folding of the polypeptide chain as a result of interactions between the side chains of amino acids that lie in different regions of the primary sequence.

32
Q

What are tertiary structures stabilized by?

A
  • hydrophobic interactions with proteins
  • hydrophilic interactions on the surface of the protein
  • disulphide bonds between cysteine residues
33
Q

What is the quarternary structure of proteins?

A

The fourth level which consists of the interactions between different polypeptide chains in proteins composed of more than one polypeptide.

34
Q

What is the structural organization of the cell membrane?

A

Bilayer of amphipathic phospholipids with associated proteins and other specialized proteins.

35
Q

How do lipid bilayers behave?

A

As dynamic, two-dimensional fluids in which individual molecules are free to rotate and move in lateral directions.

36
Q

What characteristics of lipids determine membrane fluidity?

A
  • membranes with short chain fatty acids are less rigid
  • unsaturated fatty chains increase membrane fluidity
  • cholesterol makes the membrane less fluid at the region where it is inserted
37
Q

What do channel proteins do?

A

Form open pores through the membrane, allowing free passage of any molecule of the appropriate size and structure

38
Q

What do carrier proteins do?

A

Selectively bind and transport specific small molecules, such as glucose

39
Q

What is passive transport?

A

A process where molecules are transported by either channel or carrier proteins across membranes in the energetically favourable direction

40
Q

What is active transport?

A

A process where molecules are transported in an energetically unfavourable direction (against the concentration gradient) across a membrane if their transport is coupled to ATP hydrolysis as a source of energy