Introduction to cell biology Flashcards
What are the most abundant atoms in the universe?
- Hydrogen
- Helium
When did the atoms of the universe form?
About 13.7 billion years ago
What occured when the atoms formed?
- creation of light
- Especially red and infrared light
Where in our current universe is now the place where the light that surrounds us was originally formed?
46 billion light years away
How many of the elements on the periodic table of the elements occur naturally?
94
What is a chemical reaction?
Modification of a molecule (most often: change of position of electrons in the molecule)
Why do living entities use chemical reactions/regulate chemical reactions?
- grow
- accomplish tasks
- manipulate the environment
What are salts?
Ions held together by ionic bonds
Why do ionic bonds break up in water?
Being neutralized by a lot of small charges (i.e. by water) is more stable than being neutralized by an ionic bond
What are the elements that compose cells?
- carbon
- hydrogen
- nitrogen
- ozygen
- others (phosophorus and sulfur)
What is the most abundant element in cells?
Hydrogen
Are lipids hydrophobic or hydrophiliac?
hydrophobic because of the length of the chain, which makes it very stable
What are the different molecules formed by CHNOPS elements in the cell?
- water
- sugar
- lipids
- neucleic acids
- amino acids
What percentage of the cell mass is made up of sugars?
15%
What percentage of the cell mass is made up of lipids?
10%
What percentage of the cell mass is made up of nucleic acids?
15%
What percentage of the cell mass is made up of amino acids?
50%
What is a ribozyme?
Strand of RNA that can catalyze a chemical reaction.
What is an enzyme?
A protein that can catalyze chemical reactions
What is tRNA?
Small strands of RNA that hold amino acids who can be strung together easily to make new proteins.
What is a ribosome (from an anatomical point of view)?
Strands of RNA and amino acids
What is the function of a ribosome?
- creation of protein by linking the amino acids held by tRNA molecules
- TRANSLATION of RNA into protein
What is the mechanism of RNA translation?
1) the small unit grabs to a long strand of RNA
2) the large subunit identifies tRNA molecules that complement the RNA strand
3) the ribosome removes the corresponding amino acid from the tRNA
4) the ribosome links the new amino acid to the previous amino acid
5) the ribosome takes a step and goes on to the next codon
What are the advantages of DNA?
- more stable and durable than RNA (better for info storage)
What is DNA transcription?
Sections of DNA are transcribed into strands of RNA so that they can be translated by RNA.
What is RNA translation?
The info from RNA strands are translated into chains of amino acids
What is the difference between transcription and translation?
Transcription: nucleotide –> nucleotide
Translation: nucleotide –> amino acid
What is a phospholipid?
Strand of fat with a phosphate cap
What structure do phospholipids tend to form? What does it look like?
- form bilayer sheets
- two layers of phospholipids, with the phosphate outside and the lipid inside
What do phospholipids form when shaken?
micelles, which often reform as liposomes
How did the first cells form?
Liposomes were forming an busting erratically, then chains of protein entered the bilayer, stabilizing it.
What does the prokaryotic cell contain?
- loose strands of DNA
- loose strands of RNA
- Ribosomes
What is the structure of a prokaryotic cell?
- Cell membrane
- Cytoplasm
- No organells with a wall inside
What type of molecule serves as enzymes, form receptors, serve as messengers and form the cytoskeletton?
Proteins
What are the differences between a prokaryotic cell and a eukaryotic cell?
- The eukaryotic cell has a mitochondria
- the eukaryotic cell has a nucleus
What is the function of a mitochondria?
Creates ATP by digesting sugar molecules
What is the use of ATP
- source of energy
- allows protein to act/conduct their purpose
What is the function of the nucleus?
imprisons the long strands of DNA (protection)
How do molecules get energy from ATP?
The momentum that comes from cutting off the third phosphate group
What are called the compacted strands of DNA inside a nucleus?
chromosomes
What do we call the entirety of the DNA in a cell?
Genome
What are the sections of the genome that code for a specific protein and later get transcribed and translated?
Genes
How does DNA communicate information to the rest of the cell?
1) translates a segment of DNA (gene) into RNA
2) RNA exits the nucleus
3) RNA is translated by ribosomes
What are called all the different versions of a protein that are made from a single gene?
isoforms
Where is the nucleus located?
In the soma
What are the components of the Soma?
- Cytoplasm
- Cell membrane
- Microtubules
- Mitochondria
What structure defines the boundaries of the cell? What is it composed of?
The membrane is composed of phospholipids
What is the cytoplasm?
- inside the membrane
- water filled with salt, sugar, nucleic acids, amino acids
What structures allow for rapid transport of material throughout the neuron?
Microtubules
What person advanced the field of neuroscience the most?
Darwin
What is the dominantly used species in neuroscience research?
Rodents
What is the particularity of the human brain compared to other species?
Neoteny (prolongation of maturation: the brain continues to form new links between neurons/neurons and neurons/cells, other types of brains cells that protect and support neurons continue to replicate, neurons grow bigger)
What is the original weight of a human brain? The final wieght?
.35 kg
1.4 kg
What are the functions of RNA?
- Storage for genetic information, protein-building
instructions - Can be ‘read’ or translated by ribosomes to make amino acids
What type of information does DNA contain relating to proteins?
- how to create them
- when to create them
- how much of each type to create
What structure allows the eukaryotic cell to create a lot more protein that the prokaryotic cell?
Mitochondria (produces basically unlimited energy)
What molecule is responsible for the transcription of DNA?
mRNA (messenger RNA)
What part of the brain processes the left visual field?
Right hemisphere
What part of the brain processes the right visual field?
Left hemisphere
