Biochemistry Of Microbial Growth (Chapter 7 + 3) Flashcards
All living cells can-
Grow, Reproduce, Metabolize, and Respond to their environment
Break down molecules to use to build the molecules needed in the cell =
Metabolize
How can a living cell respond to their environment?
Detect chemical + physical properties and adjust to promote survival
Growth and reproduction mean the same thing whenever talking about microbes.
True or false?
True
An increase in a population of microbes (due to reproduction) =
An increase in microbe growth
What are the results of microbial growth?
Discrete Colony + Biofilm
An aggregation of cells arising from a single parent cell =
Discrete Colony
Collection of microbes living on a surface in a complex community =
Biofilm
Organisms use a variety of what for their energy needs + to build organic molecules and cellular structures?
Nutrients
Most abundant elements in cells (Macronutrients) =
Hydrogen
Carbon
Oxygen
Nitrogen
Sulfur
Phosphorus
Macronutrients make up how much of the dry weight of cells?
99%
Are Trace Elements the same thing as Micronutrients?
Yea
Name off the nutrients that organisms need in very small/ trace amounts
Sodium
Potassium
Magnesium
Zinc
Iron
Calcium
Molybdenum
Copper
Cobalt
Manganese
Many kinds of micronutrients are needed by enzymes so that what can be carried out?
Metabolism
The 4 most abundant elements in living matter =
Carbon, Oxygen, Nitrogen, Hidrogen
The 4 most abundant elements in living matter are able to form strong bonds with other atoms to create -
Molecules
Organic molecules contain-
Carbon + Hydrogen Atoms
What are living things made of?
Organic Molecules
Inorganic molecules can contain carbon or hydrogen but not both.
True or false?
True
Functional groups combine with carbon chains to form large biomolecules called-
Macromolecules
What are the 4 types of macromolecules of life?
Carbohydrates, Lipids, Nucleic Acids, Proteins
Guess the macromolecule!
Function = Energy storage, receptors, food, structural role in plants, fungal cell walls, exoskeletons of insects
Carbohydrates
Guess the macromolecule!
Function = Energy storage, membrane structure, insulation, hormones, pigments
Lipids
Guess the macromolecule!
Function = Storage + Transfer of genetic info
Nucleic Acids
Guess the macromolecule!
Function = Enzymes, structure, receptors, transport, structural role in the cytoskeleton of a cell and the extracellular matrix
Proteins
Besides lipids, macromolecules are made from smaller molecules that act as “building blocks”. What are these molecules called?
Monomers
When many monomers get linked together =
Polymer
Lipids are mostly made of-
Carbon + Hydrogen
Aside from carbon and hydrogen, lipids can also contain-
Oxygen, Nitrogen, Sulfur, and Phosphorus
Source of nutrients, energy storage, structural of cell parts/ products =
Lipid Functions in the Cell
Fatty Acids + Triglycerides are both examples of-
Lipids
A type of lipid with long-chain hydrocarbons that end with a carboxylic acid functional group =
Fatty Acids
Water fearing / non-polar =
Hydrophobic
Are fatty acids hydrophobic?
Yes
2 types of fatty acids =
Saturated + Unsaturated
If a fatty acid is saturated, then that means that all of the bonds to carbons in the fatty acid chain are-
Single bonds
When does a single bond occur?
When 2 atoms share one pair of electrons
An unsaturated fatty acid has places in its fatty acid chain where what kind of bond causes a bend in the fatty acid tail?
A Double Bond
When does a double bond occur?
When 2 atoms share 2 pairs of electrons
Carbon can make up to how many bonds/ double bonds?
4 Single Bonds or 2 Double Bonds
A naturally occurring, 3-carbon odorless liquid =
Glycerol
When are triglycerides formed?
When 3 fatty acids are chemically linked to a molecule of glycerol
Triglycerides are considered to be what kind of lipids?
Simple Lipids
Why are triglycerides considered to be simple lipids?
Because just two compounds are required to make one (Glycerol + Fatty Acids)
Excellent sources of energy and are usually found as body fat in humans + animals =
Tryglicerides
When triglycerides are found in microbes, they are used as an-
Energy Source
These are considered to be complex lipids =
Phospholipids
How many components do phospholipids have?
More than 2
What are the components that make up a phospholipid?
A Phosphate Group + Glycerol + Fatty Acid Chains
Only how many fatty acid chains can be present in a phospholipid?
2
Why can only 2 fatty acid chains be present in a phospholipid? It’s because the-
Glycerol molecule is already busy interacting with the phosphate group
Phospholipids have what kind of head?
A Hydrophilic Head
Phospholipids have what kind of tails?
Hydrophobic Tails
The molecular composition of bacterial + eukaryotic cell membranes is similar to -
Phospholipid Bilayer Membranes
What region of a phospholipid is made of fatty acid chains and is repelled by water?
The Hydrophobic Region
What region of the phospholipid is made of glycerophosphate + a variety of other functional groups and is attracted to water?
The Hydrophilic Region
Because the hydrophobic region of a phospholipid is attracted to water and the hydrophobic region is repelled by water, the hydrophilic regions face the extracellular environment + cell cytoplasm which forms a-
Phospholipid Bilayer
Where are phospholipids found in cells?
The Cell Membrane
The Cell Membrane can also be called the-
Plasma Membrane or Cytoplasmic Membrane
Inner contents of a cell =
Cytoplasm
Membrane that separates the inner contents of the cell (cytoplasm) from the external environment =
The Cell Membrane
The Cell Membrane is a major component of what is known as the-
Cell Envelope in Bacteria
The Outer-Membrane is only a part of the cell envelope in-
Gram Negative Bacteria
The structures of a cell that are more external than the Cell Membrane + Cell Wall + Outer-Membrane (Only for gram negative bacteria) are all considered to be-
Not a part of the cell envelope
Along with the cell membrane, cell wall, and outer membrane, name a major component of the prokaryotic cell envelope =
Glyocalyx
A series of layered structures that surround the cytoplasm + govern the cellular interactions with the external environment =
Cell Envelope
Provides structure + Shape to the cell =
Cell Envelope
Protects from osmotic forces (otherwise the cell would burst) =
Cell Envelope
Aids in attachment to other cells =
Cell Envelope
Can help some bacteria resist anti-microbial drugs =
Cell Envelope
Allows import + export of materials in a cell =
Cell Envelope
Surrounds cytoplasm, separating it from the environment =
Cytoplasmic Membranes
Cytoplasmic Membranes are beneath the-
Glycocalyx + Cell Wall
Cytoplasmic membranes are also called-
Cell Membranes or Plasma Membranes
What are cytoplasmic membranes made of?
50% Phospholipids
50% Proteins
The Phospholipid Bilayer is a structure of a-
Cytoplasmic Membrane
Describes our current understanding of cell membrane structure =
Fluid Mosaic Model
According to the fluid mosaic model, what do membranes have?
Movement
Dotted with various proteins =
Mosaic
Proteins + Lipids are free to flow laterally within the membrane =
Fluid
Membranes don’t just stay in one fixed spot.
True or false?
True
The Cytoplasmic Membrane is -
Selectively Permeable
Allows some things to enter the cell while preventing others =
Cytoplasmic Membrane
The Cytoplasmic Membrane is naturally-
Impermeable to most substances
Ions and molecules with an electric charge are repelled by-
The Cytoplasmic Membrane
Can large molecules pass through the cytoplasmic membrane?
No
The Phospholipid head is hydrophilic, but the tails are hydrophobic. Is a phospholipid considered hydrophilic or hydrophobic?
The overall membrane of a phospholipid is considered to be hydrophobic
Glucose + Amino Acids are both-
Hydrophilic Substances
Do Hydrophilic or Hydrophobic substances need assistance across the cytoplasmic membrane?
Hydrophobic substances don’t need assistance, Hydrophilic substances need assistance
Oxygen + Carbon Dioxide are both considered to be what kind of substance?
Hydrophobic
Lipids + Gases are-
Hydrophobic Substances
Proteins are made up of monomers called-
Amino Acids
Amino Acids are usually made up of -
Carbon, Hydrogen, Oxygen, and Nitrogen
There are about how many amino acids that in different combinations lead to all the different proteins available in a cell?
~ 20 Different Amino Acids
If a protein can catalyze chemical reactions within the cell then it is called a-
Enzyme
Proteins can either be structural components or enzymes.
True or false?
True
A protein can take on a particular shape that allows it to do a specific job in the cell. This depends on-
The order of amino acids in a protein
The primary structure of a protein is called a -
Polypeptide
Amino acids are joined together by-
Peptide Bonds
Can some proteins remain as simple polypeptides in their original structure instead of changing?
Yes
Can proteins be modified inside the cell to achieve a more complex secondary, tertiary, or quaternary structure?
Yeah
Protein consisting of more than 1 amino acid chain =
Quaternary Protein Structure
3-Dimensional folding pattern of a protein due to side chain interactions =
Tertiary Protein Structure
Local folding of the polypeptide chain into helices or sheets =
Secondary Protein Structure
Sequence of a chain of amino acids =
Primary Protein Structure
Most enzymes are-
Proteins, but can have non-protein portions
Inactive Enzyme =
Apoenzyme
Active Enzyme =
Holoenzyme
What does a Holoenzyme require?
Binding a cofactor, coenzyme, or both
Non-Protein substance, usually a trace element (like iron or manganese) =
Cofactor
Loosely and often transiently bound to an enzyme; can associate with multiple different enzymes =
Coenzyme
Enzymes can help build things =
Anabolize
Enzymes can help break down things =
Catsbolize
Anabolism + Catabolism =
Metabolism
All cells use what to make their structures?
Protein
Proteins are important structural components for-
Ribosomes, the bacterial cell wall, external structures (used for motility + attachment)
Used to generate motion + propel the microbe through its environment =
Flagella (Singular: Flagellum)
How many Flagella can a cell have?
Some cells may have one, others have many
100s per cell, used as a way to stick to surfaces =
Fimbriae (Singular: Fimbria)
Internal cell structures that make proteins =
Ribosomes
Found just outside the cell membrane =
The Cell Wall
Used to stick to surfaces + other microbes =
Pili (Singular: Pilus)
There’s usually how many Pili in a cell?
Only 1 to a few per cell
Pili can be used for a type of motility called-
Twitching Motility
When a microbe repeatedly stretches out a pilus, attaches to the surface in front of it and pulls itself toward that attachment point =
Twitching Motility
The bacterial cell wall is made of-
Protein + Sugars
Needed to withstand osmotic/ turgor pressure to prevent cell lysis =
This is one of the functions of the cell wall in bacteria
Maintains cell shape, rigidity, provides strength + durability to a cell
This is one of the functions of the cell wall in bacteria
Most bacteria are separated into 2 groups based on -
The structure of the cell wall + Amount of peptidoglycan it contains
How can structural differences in the bacterial cell wall be determined?
By using a process called Gram Staining
Allows us to visually distinguish between 2 groups of bacteria (Gram-Positive Bacteria & Gram-Negative Bacteria) =
Gram Staining
Gram-Positive Bacteria have a-
Thick peptidoglycan cell wall
Gram-Negative Bacteria have a-
Thin peptidoglycan cell wall
Gram positive bacteria has how many layers of peptidoglycan?
30-40
Gram negative bacteria has how many layers of peptidoglycan?
1-3 layers of peptidoglycan
Is peptidoglycan found anywhere else other than bacteria?
No
What is a basic building block (monomer) of peptidoglycan made of?
The sugar backbone is made up of-
2 different types of sugars. (NAG + NAM)
NAG stands for-
N-acetylglucosamine
NAM stands for-
N-acetylmuramic acid
What is a basic building block (monomer) of peptidoglycan made of?
The protein part is made of a-
Short peptide that’s attached to NAM
How do new units (monomers) get added to a cell wall?
By attaching the sugar parts together. Then peptides form between the monomers
Whenever peptides form between monomers, it’s building the-
Network of peptidoglycan that surrounds bacterial cells
What do ribosomes synthesize?
Proteins
What are ribosomes composed of?
Protein + RNA (rRNA, a type of Nucleic Acid)
How many ribosomes are in bacterial cytosol?
Thousands of
Eukaryotic cytosol contains ribosomes that are -
Larger + Have more molecules of RNA
Most of the ribosomes in eukaryotic cells are attached to the-
RER (Rough Endoplasmic Reticulum)
The size of a ribosome is determined by-
Sedimentation Rate
Rate at which a ribosome moves to the bottom of a test tube during centrifugation =
Sedimentation Rate
Do large, compact, heavy molecules settle slower or faster than small, loosely packed, lighter particles?
Faster
Do larger/ more dense particles get a higher or lower number or Svedberg (S) Unit?
Higher
Do small, loosely packed, lighter particles get a higher or lower number or Svedberg (S) Unit?
Lower
A large subunit for prokaryotes is-
50 S
A small subunit for prokaryotes is-
30 S
A whole ribosome for prokaryotes is-
70 S
A large subunit for Eukaryotes is-
60 S
A small subunit for Eukaryotes is-
40 S
A whole ribosome for Eukaryotes is-
80 S
Most abundant micro-molecules on earth =
Carbohydrates
Primarily made of carbon + water =
Carbohydrates
Carbohydrates functions?
Food Sources, Energy Storage
Cellular Structures
Store + Transmit Genetic Info
Simple Sugars =
Monosaccharides
End in “-ose” suffix =
Monosaccharides
How are monosaccharides named?
By how many carbons in it
What happens if a monosaccharide has 4 carbons or more?
It usually takes on a cyclic structure that’s more stable
2 sugars linked together by glycosidic bonds =
Disaccharide
Disaccharides are an example of-
Dehydration Synthesis
Are disaccharides a common source of energy?
Yup
Are disaccharides easily broken down?
Yeah
Polymers of repeating sugars, but these aren’t sweet =
Polysaccharides
Are glycosidic bonds found in Polysaccharides along with disaccharides?
Yes
Polysaccharide structural function?
Cellulose cell wall in plants
Polysaccharide energy storage functions?
Starch in plants + Glycogen in bacteria and animals
2 types of glycocalyx?
Biofilm + Capsule
Don’t forget that sugar is a major component of -
Peptidoglycan (Which is used for the cell wall)
Gelatinous, sticky substance that surrounds the outside of some bacterial cells =
Glycocalyx Structure
Glycocalyx structures are usually made of-
Polysaccharides, but can be made with polypeptide or some combination of both
Produced inside the cell and are extruded on the cell’s surface =
Glycocalyx Structure
Glycocalyx Structure Functions?
Protect cells from drying.
Help pathogens survive and cause disease
What are the 2 types of Glycocalyx Structure?
Capsule + Slime Layer
Organized, repeating units of organic chemicals firmly attached to cell surface =
Capsule
Chemicals in capsules are similar to -
Chemicals normally found in the human body
Capsules prevent the human body from -
Recognizing Invaders
Capsules protect bacterium from-
Being cleared by the immune system
Why is it difficult for immune cells to engulf and kill encapsulated invaders?
Capsules are slippery
What can help visualize a capsule?
Capsule Stain
A bacterium that makes a capsule =
Bacillus anthracis
The Slime Layer is-
Loose + Water-Soluble
Slime layers allow bacteria to attach to surfaces forming -
Biofilms
What are biofilms?
Aggregates of many bacteria living together on a surface
Biofilms can form on things like-
Wounds, tissue surfaces, medical implants / devices, etc.
Bacteria in biofilms are more protected from-
Antibiotics + Drying Out
Can biofilms make it difficult to treat some infections?
Yes
