Chapter 1 + 2 Flashcards
(211 cards)
1
Q
Importance of water
A
- Most abundant compound in our bodies
- Main solvent for many organic molecules present
- Ideal medium for metabolism
2
Q
H2O structure
A
- Single oxygen atom (negative charge) covalently bonded with two hydrogen atoms (positive charge)
3
Q
Water molecules are highly…
A
Cohesive
4
Q
Water molecules are cohesive meaning
A
Individual molecules of water are highly attracted to another
5
Q
Causes of water being cohesive
A
- Hydrogen bonding
- Slight positive/negative charges
6
Q
Properties of water (8)
A
- Boils at 100 degrees Celsius
- Less dense as ice
- Transparent
- High specific heat capacity
- Evaporative cooling
- pH of 7 (pure)
- Surface tension
- Naturally exists in 3 states
7
Q
Reasons for boiling point at 100 degrees
A
Hydrogen bonds no longer hold together molecules
8
Q
Reasons for ice being less dense
A
- Less movement within molecule when frozen
- Lattice shape
9
Q
Hydrophilic definition
A
Substances that dissolve readily in water
10
Q
Other terms for hydrophilic
A
Polar, lipophobic
11
Q
Hydrophobic definition
A
Substances that do not dissolve readily in water, but dissolve readily in lipids
12
Q
Other terms for hydrophobic
A
Non-polar, lipophilic
13
Q
Examples of hydrophobic substances
A
Alcohol, ether
14
Q
How substances dissolve
A
The positive and negative charge of water attracts ions in substance and break substance apart causing it to ionise.
15
Q
How pH is worked out
A
Ratio of OH- and H+ ions
16
Q
Neutral pH
A
7
17
Q
Acidic pH
A
Less than 7
18
Q
Basic pH
A
More than 7
19
Q
How pHis kept constant by body
A
Cells produce and use hydrogen ions
20
Q
Hydrogen bonds maximum partners (in water)
A
4
21
Q
Main types of organic molecules
A
Carbohydrates, lipids, proteins, nucleic acids
22
Q
Monomers definition
A
Smaller molecules (subunits) that give rise to the polymer
23
Q
Polymer definition
A
Molecules that consist of many repeating subunits
24
Q
How polymers are formed
A
Condensation reactions,
Anabolic, endergonic
25
How polymers are broken down
Hydrolysis reaction
| Catabolic, exergonic
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Carbohydrates elements
Carbon, hydrogen, oxygen
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Ratio of elements in carbohydrates
1:2:1
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Subunits of carbohydrates
Monosaccharides, disaccharides
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Polymer of carbohydrates
Polysaccharides
30
Monosaccharides
A molecule that is comprised of a single sugar unit
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Polysaccharides
A molecule that is comprised of many sugar units
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Disaccharides
Molecule that is comprised of two sugar units
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Monosaccharide examples (4)
Glucose, fructose, galactose, mannose
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Glucose
- hexose sugar
- most common source of energy
- C6H12O6
35
Two types of glucose
Alpha and beta glucose
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Fructose
Pentose sugar, in fruit
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Disaccharide examples (3)
Sucrose, maltose, lactose
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Sucrose
Glucose + fructose
Processed sugar
Form in plants (phloem)
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Lactose
Glucose + galactose
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Maltose
Glucose + glucose
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Polysaccharide examples (6)
Starch, glycogen, cellulose, chitin, pectin, inulin
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Starch properties (branched or not, role, solubility, type of glucose)
Branched
Storage of energy in plants (granules)
Slightly soluble
Alpha glucose
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Glycogen properties (branched or not, role, solubility, type of glucose)
Highly branched (more than cellulose)
Energy storage in animals
Slightly soluble in water
Alpha glucose
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Cellulose properties (branched or not, role, solubility, type of glucose)
Unbranched
Structural component in cell walls of plants used for structure and strength
Insoluble
Beta glucose
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Energy storage in plants (not just starch)
Granules in amyloplasts
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Simple carbohydrates
Carbohydrates containing one or two sugar units
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Complex carbohydrates
Many sugar units
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Inorganic compounds examples
Salts, water, O2, CO2, minerals
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Bonding that holds together carbohydrates
glycosidic linkages
50
Lipid elements
carbon, hydrogen, oxygen
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How to tell difference between lipid and carbohydrate
in lipid, there is usually much less oxygen
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Do lipids or carbohydrates produce more energy
lipids as they are more dense
53
Examples of lipids (4.5)
fats and oils, phospholipids, waxes, steroids
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Fats and oils are known as
triglycerides/triacylglycerols
55
Triglycerol comprised of
single glycerol molecule bonded to 3 fatty acid tails
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Are lipids polymers
no, as their subunits are discrete and non-repeating
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Are lipids soluble in water
no
58
How are triglycerides stored in the body
adipose tissue
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Purpose of adipose tissue
protects vital organs by cushioning, absorbs impact, insulator, source of fats, energy
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Cholesterol structure
4 rings
61
Purpose of cholesterol in phospholipid bilayer
fluidity to prevent solidification, keeps in place, acts as barrier between phospholipids
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Use of steroids
signalling molecules, muscle repair
63
Use of wax
surface coating
64
Phospholipids definition
A lipid molecule found in the membranes of cells, that are comprised of a glycerol molecule attached to a hydrophilic phosphate head, and a two hydrophobic fatty acids tails.
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Phospholipids structure
phosphate group, glycerol molecules, two fatty acid molecules
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Are fatty acids of phospholipids saturated or unsaturated
one is saturated, one is unsaturated
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Unsaturated meaning
if have one or more double carbon bonds
68
Saturated meaning
are saturated with hydrogens; have the maximum possible number of hydrogens
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Is phospholipid hydrophilic or hydrophobic
head is hydrophilic, tails are hydrophobic
70
Why do fatty acid tails face in
because they are hydrophobic
71
Amino acid elements
C, H, O, N, generally S
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Subunits of proteins
amino acids
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How many naturally occurring amino acids are there
20
74
Amino acids can be (polarity e.t.c.)
nonpolar, polar, electrically charged, acidic or basic
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Structure of amino acid
carboxyl group (-COOH), amino group (-NH2), variable R/Z group
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Dipeptide
2 amino acids
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Tri-peptide
3 amino acids
78
Polypeptide
many amino acids
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When to call it protein vs polypeptide
it’s a protein if it’s extremely long, multiple separate amino chains, globular
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Globular proteins
soluble, lock and key
81
Examples of globular proteins (5)
enzymes, messenger molecules, membrane channel/carrier proteins, regulatory proteins, defensive
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Fibrous proteins
insoluble, structural use
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Amino acids are….
directional
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Type of bonding amino acids use
peptide bonding
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Secondary structure
localised coiling and folding of segments of the polypeptide chain through hydrogen bonding
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The two types of secondary structure folding
alpha helices, beta pleated sheet
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Tertiary structure
overall 3-D structure and irregular folding of the protein due to global coiling and folding
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What controls function of protein/enzyme
tertiary structure
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Quaternary structure
multiple polypeptide chains (held together through hydrogen bonding, ionic interactions, covalent bonding and hydrophobic interactions) that form a final protein
90
Two types of nucleic acids
DNA, RNA
91
DNA stands for
deoxyribonucleic acid
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RNA stands for
ribonucleic acid
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Locations of DNA
nucleus, mitochondria, chloroplast
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Types of RNA
messenger, transfer, ribosomal
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mRNA
transcription
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tRNA
carries amino acids for translation
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rRNA
structural component of ribosomes, also located in nucleolus
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Monomers of nucleic acids
nucleotides
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Two types of nucleotides
DNA nucleotides, RNA nucleotides
100
DNA nucleotide structure
deoxyribose, phosphate group, nitrogenous base
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RNA nucleotide structure
ribose, phosphate group, nitrogenous base
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Nitrogenous bases in DNA
cytosine, guanine, adenine, thymine
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Nitrogenous bases in RNA
cytosine, guanine, adenine, uracil
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A-T bond number
2
105
C-G bond number
3
106
Purines
adenine, guanine
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Pyrimidines
cytosine, thymine, uracil
108
DNA is…..
directional
109
What is a polynucleotide
single strand ?
110
DNA structure
double helix, two strands that run anti-parallel
111
How to identify three/five prime ends
five has the extra group
112
What holds the two strands of DNA together
hydrogen bonding
113
Diffusion
the net, passive movement of molecules from a region of high molecule concentration to a region of low molecule concentration, until equilibrium is achieved. It does not require energy.
114
When does diffusion stop
when the equilibrium is achieved
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For diffusion, bigger SA:V ratio means
quicker diffusion
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Facilitated diffusion
is the net movement of a substance through a plasma membrane via protein channels or protein carriers, from a region of high concentration to a region of low concentration
117
Important thing to remember about carrier/channel proteins in facilitated diffusion
each carrier only allows for certain substances to cross
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Osmosis
net movement of water molecules across a semipermeable membrane from a region of high water concentration (low solute concentration) to an area of low water concentration (high solute concentration)
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Osmosis affects the ….. of a solution
tonicity
120
Hypertonic
high solute outside, osmosis out of cell
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Hypotonic
low solute outside, osmosis into cell
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Isotonic
no net osmosis
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What happens when plant cells are in hypertonic
plasmolysis
124
Active transport
the net movement of dissolved substances into or out of cells against a concentration gradient, from an area of low substance concentration to an area of high substance concentration. It is an energy requiring process.
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Reasons for active transport
allows us to maintain homeostasis, need greater amount than can be provided
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Endocytosis
a process involving the entry of substances into the cell by the formation of a vesicle from the plasma membrane
127
Phagocytosis
bulk transport of solid particles.
128
Pinocytosis
bulk transport of liquids/fluids
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Exocytosis
process of bulk transport of materials out of the cell through being secreted via a vesicle
130
What to use when protein vs waste exocytosis
protein is secreted, waste is expelled/voided
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Plasma membrane
partially permeable boundary of a cell separating it from its physical surroundings.
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Name of model
fluid mosaic model
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Fluid mosaic model
phospholipid bilayer + proteins, antigens, cholesterol, self molecules
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Substances that pass rapidly through lipid bilayer (gaps)
O2, CO2, water, amino acids, urea
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Channel proteins
form aqueous pores allowing specific solutes to pass through the membrane
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Carrier proteins
bind to solute and undergo a conformational change to transport the solute across the membrane. (if no energy is required, called facilitated diffusion).
137
Cytosol
fluid component of cell which consists mainly of water and dissolved substances. (excludes organelles + nucleus)
138
Cytoplasm
cytosol + organelles except the nucleus.
139
Protoplasm
cytosol + organelles + nucleus
140
Cytoskeleton
protein filaments that keep structure of cell
141
Parts of cytoskeleton
microfilaments, microtubules, intermediate filaments
142
Are cytoskeletons in prokaryotes
no
143
Cell walls found in
bacteria, plants, fungi
144
Nucleus
a membrane bound organelle containing the genetic material DNA. The control centre.
145
Structure of Nucleus
souble nuclear envelope that is porous, nucleolus inside, fluid inside, granules
146
Mitochondrion
site of aerobic respiration in eukaryotic organisms
147
Structure of mitochondrion
double membrane, cristae = folds, matrix fluid, own DNA, own ribosomes
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Ribosomes
sites of protein production in cells in both prokaryotes and eukaryotes
149
Free ribosomes
produce ribosomes for use within cell
150
ER
organelle consisting of membrane bound channels
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Rough ER
produces and transports proteins (for use outside of cells)
152
Smooth ER
produces and transports lipids for use outside of cell
153
Synthesis of protein for use outside of cell
produced in rough ER, transported via vesicle to golgi, where is is modified and packaged into vesicle which travels to cell membrane and fuses - protein is secreted
154
Golgi complex
organelle that packages material into vesicles for export from a cell
155
Other names for golgi complex
Golgi body, Golgi apparatus
156
Endosomes
digest products brought in via endocytosis
157
Lysosomes
break down unwanted particles in cell
158
Perioxomes
break down unwanted particles produced by metabolism
159
Cilia/flagella purpose
movement
160
Chloroplasts
chlorophyll-containing organelles that are responsible for photosynthesis in plant cells
161
Thykaloids
membrane structures in grana
162
Grana
membrane stacks that contain chlorophyll; site of light dependent stage in photosynthesis
163
Stroma
fluid in chloroplast
164
Types of junctions
occluding junctions, communicating junctions, anchoring junctions
165
Desmosomes
type of cell-to-cell junction in which protein filaments span the intercellular space and hold cells together.
166
Plasmodesmata
openings between plant cell walls through which adjacent cells are connected through cytoplasmic thread.
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Plasmodesmata allows plants to
communicate cell to cell
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Plastids
found in plants and protists
169
Centrioles
organise spindle fibres
170
Two pathways
mitochondrial pathway, death receptor pathway
171
Mitochondrial pathway
mitochondria signalled, breaks down, caspases ????
172
Death receptor pathway
lysosomes destroy them from outside of cell, caspases enter cell, breaks down, blebs, organelles break down, fragments phagocysed ?????
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Types of variables in experiment
independent, dependent, control, extraneous
174
Other names for independent variable
experimental variable, tested variable
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Controlled variables
variables that are deliberately kept constant during the course of the experiment
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Extraneous/uncontrolled variables
variables in the experiment that may introduce errors to the results, typically caused due to faults in experimental design
177
Purpose of a control
as a comparison in order to see the effects of the independent variable
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Why does repeating the experiment increase validity of results
reduces the effect of random error
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Can a hypothesis be proven
no, only disproven.
180
Steps for an experiment
1. Set up two groups - one control, one experimental
2. Keep all other factors constant.
3. How/when you are going to measure the independent variable
4. Repeat the experiment many times.
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Characteristics of living organisms
MRS GREN
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MRS GREN stands for
Movement, Respiration, Sensitivity to stimuli, Growth and repair, Reproduction, Excretion, Nutrition
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Organisation of life
atoms, molecules, organelles, cells, tissues, organs, organ systems, organism, population, community, ecosystem.
184
Prokaryote
cell that lacks membrane bound organelles
185
Eukaryote
cell that contains membrane bound organelles
186
Synchrotron
microscope used to examine molecules
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Cell theory
all living organisms are composed of one or more cells, cells are the basic functional unit of life, all new cells arise from pre-existing cells
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Five kingdoms
bacteria, animals, plants, protists, fungi
189
What polysaccharides are in the body?
Glycogen
190
Structure of chitin monomer
Glucose molecule with a nitrogen containing unit i.e. amino group
191
How much more energy per gram do lipids provide than glucose
Twice the energy
192
Where is fat stored
Adipose tissue
193
Function of cholesterol (TSFX)
Reduces membrane fluidity by reducing moderate temperature, but it also hiders solidification at low temperatures
194
All steroids start of as
Cholesterol
195
How many rings does a steroid molecule have
4
196
Purpose of glycolipids and glycoproteins
The act as self molecules for cell recognition
197
Key word to use for tertiary structure
'Conformational'
198
What does repeating an experiment do
Reduce effect of random error, increase RELIABILITY of results
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How to improve ACCURACY of results
Alter equipment
200
Two requirements of living organisms
Respiration, must be made of cells
201
Cyanobacteria do what
Photosynthesise
202
Lysosomes are found in both...
Plant and animal cells
203
Contractile vacuole
Contains a large amount of water and dissolved minerals and ions
204
What would happen if cells didn't have a contractile vacuole
The cell would burst
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What word must be used for diffusion, osmosis and facilitated diffusion definitions
Passive
206
What is the solution surrounding cells (between the cells and cell walls) after plasmolysis occurred in plant cell
Hypertonic solution
Salt solution will be accepted too for these cue cards
207
What are glycolipids
Lipids with a carbohydrate molecule attached
208
Where is chitin found
Fungi cell walls and exoskeletons of insects
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What to remember about lipids in terms of monomers and polymers
Lipids have monomers but not polymers
210
What is an organelle that animals cellar have that plant cells don't
Centriole
211
How tertiary structure holds together
hydrogen bonding, ionic interactions, covalent bonding (disulfide bridges), hydrophobic interactions (of R group)
