Brainscape's Knowledge GenomeTM

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


See full index

biochemistry > elements, molecules and cells > Flashcards

elements, molecules and cells Flashcards

1
Q

what does the matter surrounding us consist of?

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

what is the smallest unit of an element? what does it contain?

A
  • atom
  • contains nucleus with protons (+ charge) and neutrons (no charge)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what do electrons do? why is this important

A
  • orbit the nucleus, which is important for atoms combining to form large elements
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the charge of electrons equal to?

A
  • negative charge of equal absolute value to protons
  • ensures that the atom itself is neutral if electron number = proton number
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how is electron movement explained?

A
  • sophisticated
  • explained in terms of atomic orbitals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is position of electrons depicted by?

A
  • electron clouds which are denser where it is more likely to encounter electrons and thinner when less likely
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how many elements are known to make up organisms? how many make up 97% of mass of biological substance?

A
  • 26 elements
  • around six form 97%
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the abundant elements? what is an exception?

A
  • hydrogen, carbon, nitrogen, oxygen, phosphorus and sulphur
  • hydrogen is an exception due to single proton in nucleus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is the atomic number?

A
  • indicative of the number of protons in the nucleus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is atomic mass? what is it calculated in?

A
  • mass of one of the elements atoms
  • calculated in dalton (1/12th of 12C atom)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

why is the atomic mass useful?

A
  • useful in calculating how much there is of a particular element within a substance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is an isotope?

A
  • two atoms of the same element differ in number of neutrons but same atomic number
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how is molecular weight of diverse elements calculated?

A
  • multiply number of atoms by their respective atomic mass and add them together
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

where do molecules frequently reside?

A
  • in solution of water so its useful to understand their concentration
  • express concentration in moles per litre
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is Avogadro’s number?

A
  • mole of substance always equal to atomic mass in grams of the substance
  • contains 6.023 x 10^23
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is molarity?

A
  • refers to the number of moles of the substance in a given volume
  • e.g., 1 molar glucose= 1 mole of glucose in 1 litre
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what can atoms form bonds with?

A
  • atoms with the same or different elements
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what does bonding of atoms require?

A
  • at least two electrons which in most cases are contributed mutually by atoms participating
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what bond do atoms create?

A
  • when two atoms share electrons it is known as a covalent bond
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is the number of bonds an atom can form determined by?

A
  • distribution of electrons in its atomic orbitals
  • known as electronic structure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are molecules?

A
  • atoms that are joint by covalent bond
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what is a compound?

A
  • if molecules of a substance exist of atoms belonging to two elements
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is the difference between organic and inorganic compounds?

A

-organic compounds contain carbon whereas inorganic don’t e.g. water

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

what is the difference in charges between molecules and compounds?

A
  • molecules are electrically neutral
  • compounds carry electrical charge in the form of ions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what does the little number demonstrate and why is this useful?

A
  • little number shows the number of atoms
  • useful in understanding how much there is of a certain compound in a substance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is the molecular formula?

A
  • gives a complete list of all the atoms in a molecule
  • representation of a molecule that uses chemical symbols to indicate the types of atoms followed by subscripts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is the structural formula?

A
  • details the way in which atoms are connected in compounds via knowing number of bonds that each atom can form
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what is an anion?

A
  • carry electrical charge as some atoms are more stable with more electrons than protons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

what is an cation?

A
  • carry less electrons than protons so have a positive charge
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

what does radical mean?

A
  • when a molecule or ion has an unpaired electron
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what is polarity?

A
  • what degree it is polar
  • affects the physical property of miscibility
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

what is miscibility?

A
  • its ability to mix with other substances
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what are polar molecules?

A
  • have one negative and one positive pole
  • contains N, O or S connected to C or H
  • nuclei of the two elements attract bonding electrons to a similar degree
34
Q

what are non- polar molecules?

A
  • charges evenly distributed within the molecules of a compound
  • only contain C + H
  • nuclei of the two elements attract bonding electrons to a similar degree
35
Q

do polar and non- polar molecules readily mix?

A
  • no; polar tend to mix with polar while nonpolar tend to mix with nonpolar
36
Q

what is a solution?

A
  • when the mixing of two or more substances results in a homogeneous mixture
  • mixture has same composition all over its mass
37
Q

what is a solvent?

A
  • substance present in the highest proportion
38
Q

what is a solute?

A
  • consists of dissolved substances
39
Q

what is the concentration of a solute defined as?

A
  • amount of it that is contained in a certain amount of solution/ solvent
  • common unit is mole per litre of solution
40
Q

what does hydrophilic mean?

A
  • mixes readily with other polar molecules e.g., sugar
41
Q

what does hydrophobic mean?

A
  • non polar compounds do not mix readily with water e.g., oil
42
Q

what is a chemical reaction?

A
  • when substances are mixed, they interact to form new chemical entities as part of chemical reactions
    e.g., conversion of glucose to water and C02 via burning
43
Q

how are chemical reactions not just physical processes?

A
  • dissolving glucose in water means that glucose remains just in a different physical form
44
Q

what are reactants?

A
  • substances consumed during a chemical reaction
45
Q

what are products?

A
  • substance produced
46
Q

what are reversible reactions dependent on?

A
  • depending on factors associated with the surroundings
  • can go the other way under certain conditions
47
Q

what are irreversible reactions?

A
  • certain reactions go almost completely in one direction under certain circumstances
48
Q

what two laws are adhered to in order to understand chemical reactions?

A
  • principle of mass conservation
  • principle of charge conservation
49
Q

what is the principle of mass conservation?

A
  • atoms aren’t lost/ gained they are just simply rearranged
  • two sides of chemical equation must have same number of atoms
  • one may have to add numbers in front of some reactants/ products
50
Q

what is the principle of charge conservation?

A
  • ions adhere to this where there is no net increase/ decrease in charge
  • one may have to add one or more H+ to one of the two sides
51
Q

how does a balanced chemical equation comply with the two principles?

A
  • shows which compounds react and what products result as well as proportions of molecules/ moles
52
Q

what is equilibrium constant?

A
  • if a reaction is left to proceed far enough it reaches a state in which no further change is detected in the concentration of any participating substance
53
Q

what factor acts as a determinant of chemical reactions?

A
  • pH describes concentration of protons or (H+ ) in a solution
  • no relation to electrical charge
  • ease in which protons are detached/ added to chemical compounds endows them with a role in chemical processes
54
Q

what is the neutral pH number?

A
  • 7
  • pure water
55
Q

what is the pH of an acid? what happens to H+ ?

A
  • below 7
  • H+ increases
56
Q

what is the pH of an alkaline? what happens to H+ ?

A
  • above 7
  • H+ decreases
57
Q

what is the pH of most biological fluids and what is it named?

A
  • nearly neutral
  • referred to as physiological
58
Q

what does it mean if a compound in an aqueous solution can exchange protons with its surroundings?

A
  • its form isn’t foxed but depends on the pH of the solution
  • such a compound binds protons when pH decreases and loses protons when pH increases
59
Q

what does changes in pH affect?

A
  • affect the form of ionizable solutes which affect interactions among them, cells and multicellular organisms
60
Q

what is a buffer system?

A
  • expression of homeostasis
  • organisms are protected against lethal instability
  • maintain constancy of pH
61
Q

what do living organisms contain?

A
  • compounds of high buffer capacity
62
Q

what is high buffer capacity?

A
  • amount of strong acid/ strong base that needed to be added to one litre of a solution in order to change the pH by one unit
63
Q

how do high buffer capacity compounds normally come?

A
  • in pairs of conjugate acid and base which are interconverted upon absorbing/ releasing H+
64
Q

when is buffer capacity maximal?

A
  • when pH= pK
  • concentrations of conjugate acid= base
65
Q

what is pHa?

A
  • log of conjugate base concentration divided by weak acid concentration
66
Q

what is a monomer?

A
  • smaller units that are identical to each other and act as building blocks
67
Q

what are polymers?

A
  • macromolecules result from joining monomers together
68
Q

what are cells?

A
  • building blocks of living organisms
69
Q

what are eukaryotic cells described as and compromised as?

A
  • complex
  • compromise 4 kingdoms; protists, fungi, plants and animals
70
Q

what are prokaryotic cells compromised of?

A
  • two large group
  • bacteria and archae
71
Q

what are all cells enclosed in? and why?

A
  • plasma membrane
  • separates cell contents from extracellular space
  • thick and consists of lipids and proteins that carbs may attach to
72
Q

describe the cytoplasm

A
  • interior of the cell
  • main component is water
73
Q

describe ribosomes

A
  • involved in the production of proteins via protein synthesis
74
Q

describe lysosomes

A
  • involved in breakdown of proteins as they digest cell waste
75
Q

describe what nucleolus contain and the importance

A
  • contain genes for rRNA
  • essential for transcription and translation
76
Q

what does the nucleus contain and describe it

A
  • contains DNA which carries instructions
  • densest and largest part
77
Q

describe the golgi apparatus

A
  • membrane bound compartment in eukaryotic cells that modifies proteins and packages them into vesicles
78
Q

describe the mitochondria

A
  • powerhouse as it is the centre of respiratory ATP production
  • essential in lipid metabolism
79
Q

describe the endoplasmic reticulum

A
  • large membrane bound network of tubules and flat compartments called cisternae
80
Q

what is the endoplasmic reticulum continuous with and what does it do?

A
  • continuous with the outer membrane of the nuclear envelope
  • involved in protein+ lipid synthesis and storage
81
Q

what is chromatin?

A
  • DNA in eukaryotic cells found in a complex with proteins and RNA
  • aid in tight packaging of DNA during cell division
82
Q

what does the nuclear envelope do?

A
  • separates contents of nucleus from cytoplasm

biochemistry (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions