Learning objective 1.1 Flashcards
What are chemotrophs?
Organisms that use chemical compounds as their source of energy
what are phototrophs?
organisms that use (light) electromagnetic radiation as their source of energy.
what are classified as eukaryotes?
A. Plants
B. E.coli
C. Fungi
D. Animals
E. Protists
A, C, D, E
Eukaryotes are plants, animals, fungi, protists( algae, yeasts, Protozoa, and slime molds)
Animals are further classified as Metazoan
What are classified as prokaryotes?
A. Eubacteria
B. Archbacteria
C. Algae
D. Protozoa
E. Metazoan
A, and B
prokaryotes are eubacteria and archbacteria
what are metazoan?
multicellular animals with specialized tissues
list the differences between eukaryotes and prokaryotes
Eukaryotes:
- organisms with membrane-enclosed nucleus and organelles
- have complex organelles
- linear DNA
- large ribosomes (80s)
- divide by mitosis
- ETC is located in the inner mitochondrial membrane
Prokaryotes:
- organisms with no nucleus, but a nucleoid
- no complex organelles
- circular DNA
- small ribosomes (70s)
- divide by fission
- ETC is located on the plasma membrane
- has a cell envelope
- some bacteria have appendages (flagella, pili)
name and describe the characteristics that differ in animals and plants.
Lysosomes: in animals, have an acidic lumen, degrade material in the cell and worn-out cellular membranes and organelles
Microvilli: in animals, increase surface area for absorption of nutrients from the surrounding medium
cell wall: in plants, composed of cellulose, helps maintain the cell’s shape, and provides protection against mechanical stress.
vacuole: in plants, stores water, ions, and nutrients, degrades macromolecules, and functions in cell elongation during growth
chloroplasts: in plants, carry out photosynthesis, are surrounded by a double membrane, and contain a network of internal membrane-bounded sacs.
plasmodesmata: in plants, tubelike cell junctions that span the cell wall and connect the cytoplasm of adjacent plant cells
describe the Plasma membrane
- semipermeable. it controls the influx and efflux of material
- consists of amphiphilic lipids (hydrophilic head group and hydrophobic fatty acyl chain) with proteins (transmembrane proteins)
- also contains cholesterol
other structures that have a plasma membrane
besides the lipid bilayer, lysosomes also have the same structure.
describe the mitochondria
responsible for the following:
- ATP synthesis through respiration,
- lipid metabolisms (fatty acid oxidation takes place here in animals)
- pyruvate dehydrogenase reaction
- Krebs cycle
- produces antiviral responses
- involved in regulating apoptosis (cyct C controls apotosis + involved in ETC)
- has an inner and outer membrane. and is filled with foldings called cristae. the space in the cristae is the matrix
- has circular DNA and is stored in the matrix
What takes place in the mitochondria?
A. aerobic respiration
B. fatty acid oxidation
C. fatty acid synthesis
D. pyruvate dehydrogenase reaction + Krebs cycle
A, B, and D
Which of the following is found in both animals and plant cells?
A. Chloroplasts
B. Golgi Apparatus
C. Mitochondria
D. Cell Wall
E. Nucleus
F. A and E
G. A, B, and E
H. B, C, and E
H. B, C, and E
Describe the chloroplasts
- only found in plants
- ATP synthesis through photosynthesis
- FA synthesis takes place here for plants
- contains chlorophyll
what is unique about mitochondria and chloroplast
- Both have their own circular DNA
- derived from cyanobacteria
describe lysosomes
- in animals
- degrade structures and molecules by acid hydrolases. break down polymers into monomers
- appear darker b/c they are degrading molecules
- lower ph (~5)
describe vacuoles (in plants)
- in plants
- responsible for degradation and storage
describe peroxisomes
- in animals, responsible for fatty acid oxidation of VERY LONG fatty acids
- synthesis of cholesterol, bile acid, and other lipids
- in plants, responsible for all fatty acid oxidation
where does fatty acid synthesis occur in animals?
in the cytosol
what makes up the Endoplasmic reticulum?
The smooth ER and the rough ER
what happens in the smooth ER?
- lipid synthesis
- drug metabolism
- detoxifies hydrophobic molecules
What happens in the rough ER?
- Protein synthesis
- Protein modification
- processing and transporting secreted proteins, lysosomes, and membrane proteins
What makes the rough ER rough?
- ribosomes
Describe what happens in the Golgi complex
- protein modification and trafficking from the rough ER
- this is where glycosylation happens
what happens in the Cytoplasm/cytosol?
- glucose degradation (aka glycolysis)
- fatty acid synthesis (in animals)
list the membrane-less structures
- Nucleolus
- P-bodies
- Cytosolic structures
What is the nucleolus?
- a nuclear subcompartment where most of the cells rRNA is synthesized and assembled
What do P-Bodies do?
- mRNA inhibition of translation and degradation
Where are p-bodies and the nucleolus located, respectively?
the cytoplasm and nucleus
what are cytosolic stress granules?
- a membrane-less organelle-like structure
- they store mRNAs under certain conditions
What is the cytoskeleton made of?
- microfilaments
- microtubules
- intermediate filaments
Describe intermediate filaments
- provide mechanical support and maintain cell structure
- made of proteins such as keratin, lamins and neurofilaments
Describe microtubules
- regulate the position of organelles
- responsible for chromosome separation
- tubulins are the proteins that polymerize to form microtubules
describe microfilaments
- regulate cell structure, shape, locomotion, and are involved in cell division
- polymerization of G actin
Describe the extracellular matrix
- it is made of materials that is produced by the cell and secreted
- it is made of proteins (mostly collagen) and carbohydrates (polysaccharides)
- the ECM supports cell adhesion to substrate in multicellular organisms
what is the endosymbiosis hypothesis?
the idea that large organelles are derived from the symbiotic relationship between prokaryotes and primitive eukaryotes through the endocytosis of prokaryotes.
- mitochondria are derived from colorless aerobic prokaryotes
- chloroplasts are derived from cyanobacteria
- later came organelle specialization and loss of organelle independence as a result. they cannot survive on their own now.
- the organelles genome only contains part of the information because of the huge endosymbiotic gene transfer (EGT)
name the evidence of the endosymbiosis hypothesis.
- Circular DNA in mitochondria and chloroplasts
- small ribosomes in large organelles
- organelle membrane contains components of the electron chain
- the division of organelles by fission
Describe viruses
- they are technically not cells
- not alive
- require a host organism to survive
- infect all types of organisms
what is the basic level of a cell?
monomeric units
list the structural hierarchy of the cell from lowest to highest
- monomeric units (nucleotides, amino acids, sugars)
- macromolecules (DNA, Protein, Cellulose)
- Supramolecular complexes (chromatin, plasma membrane, cell wall, ribosomes, cytoskeleton)
- the cell and its organelles
What are considered supramolecules?
A. DNA
B. Amino acids
C. Plasma membrane
D. Chromatin
E. Cell Wall
F. C, D, and E
F.
DNA is a macromolecule and amino acids are monomeric units
What is a bacterial cell mostly made up of?
water
What macromolecules are found in a bacterial cell?
- DNA
- RNA
- Protein
- Polysaccharide
list the cellular macromolecules
- DNA
- RNA
- Insulin
- Adenylate Kinase
- Lipid Bilayer *not a true macromolecule because it isnt held together by covalent bonds
- Immunoglobulin
- Hemoglobin
- Glutamine synthetase
What are the building blocks of the cell?
- sugars
- fatty acids
- amino acids
- nucleotides
which of the following are NOT building blocks of the cell?
A. triglycerols
B. Phospholipids
C. DNA
D. nucleotides
A, B, C
Match the following with the larger units of the cell
A. Amino acids. 1. Fats, lipids, membranes
B. Sugars 2. Nucleic acids
C. Nucleotides 3. Proteins
D. Fatty acids 4. Polysaccharides
A = 3
B = 4
C = 2
D = 1
Describe the central dogma
DNA —> RNA —> Protein.
the process by which DNA is used to produce a functional product (protein).
this represents the unidirectional flow of things
DNA becomes mRNA through transcription.
mRNA becomes protein through translation
Where do transcription and translation occur? respectively
Transcription (DNA to mRNA) occurs in the nucleus
Translation (mRNA to protein) occurs in the cytosol. the mRNA is exported out of the nucleus to the cytosol
what organisms use light vs. chemical energy sources?
Phototrophs use light as their source of energy. perform photosynthesis
Chemotrophs use chemical compounds as their source of energy. perform chemosynthesis
Classify organisms based on their source of carbon
Autotrophs - can fix CO2 themselves so carbon dioxide is their carbon source
Heterotrophs- cannot fix CO2 themselves so they rely on other organisms as their carbon source
How would humans be classified based on their energy and carbon source?
Chemoheterotrophs
Name an example of a photoautotroph
plants, algae
what would be an example of a chemoheterotroph?
fungi
what is the universal energy currency? what is it made of?
ATP (adenosine triphosphate)
made of adenine, triphosphate (3 phosphates), and a ribose
what are the 6 processes that require energy?
- heat
- making macromolecules (DNA, RNA, proteins, polysaccharides)
- making cellular and metabolic components
- movement
- transport of molecules against a concentration gradient (active transport)
- generation of electric potential across a membrane (nerve function)
Where does the energy in ATP come from?
- from cleaving one phosphoanhydride bond.
- the 3 negative phosphate groups repel each other but are forced to stay together. this makes them high energy/
- by cleaving that bond, energy is being released (that’s why it is exergonic) and it moving from a high energy state to a low energy state
how does stimuli work?
- the receptor protein in the cell membrane detects a signal from the environment
- this activates the gene-regulatory protein and it binds to regulatory DNA
- this activates a gene to produce another protein
- that protein binds to other regulatory regions of DNA
- which produce more proteins and gene-regulatory proteins
What macromolecules do we have the most of?
Protein.
Between DNA and RNA, which do we have more of? Why?
RNA. because of ribosomal rna
Why are membranes not considered true macromolecules?
They are not held together by covalent bonds
Types of cellular reproduction
asexual and sexual reproduction
