Midterm content Flashcards
What microscope is used to see cells and smaller objects?
Light microscope
What forms a light microscope?
a lens and light
Which microscope is used for studying organelles?
Transmission electron microscope
Which microscope is used for studying surface structure?
Scanning electron microscope
What is a macromolecule?
A polymer of smaller molecules
What are the 4 kinds of macromolecules?
Polysaccharides, proteins, nucleic acids, lipids (lipids are not real macromolecules)
How do molecules grow?
Dehydration reactions
How do you break down molecules?
Hydrolysis
What are polysaccharides and disaccharides held by?
Glycosidic linkage bonds
What are polysaccharides?
Polymers built of many monosaccharides, structural and storage
What are structural polysaccharides used for?
To build strong materials ex: exoskeleton
What are storage polysaccharides used for?
Store sugar in the form of storage polysaccharides (plants- starch, humans-glycogen)
what are lipids?
Diverse group of hydrophobic molecules: Consist of phospholipids, steroids, fats
What are fatty acids formed of?
Hydrocarbon chain, carbon at one end is part of carboxyl group
What is a fat?
constructed from two smaller molecules: fatty acid and glycerol
triacyglycerol?
3 fatty acids, 3 glycerol molecules
What is a phospholipid?
two fatty acids attached to glycerol, one hydroxyl group attached to phosphate
What is a saturated phospholipid?
no double bonds, completely surrounded by Hydrogen (solid)
What is an unsaturated phospholipid?
Double bond, cinched, hydrogen cannot completely surround it (liquid)
What is a phospholipid bilayer?
a hydrophilic double membrane (head is hydrophilic, tail is hydrophobic)
Explain how DNA is transcribed
DNA (transcription) - RNA (translated)- amino acid chain (folding) - protein
What are some uses for proteins?
Enzymes, antibodies, storage proteins, etc..
What are amino acids composed of?
Organic molecules with an amino group and a carboxyl group, have side chains of amino acids, join to create polypeptides
Which bonds hold proteins together?
Peptide bonds
How many amino acids are there?
There are 20 different kinds, each chain varies in order which can produce many many different proteins
What are the 4 levels of protein structure?
- Primary
- secondary
- Tertiary
- Quaternary
What occurs in the 1st phase of protein structure?
Amino acids bond to form polypeptides
What happens in the 2nd phase of protein structure?
Secondary: hydrogen bonds stabilize regions (Alpha helix and beta pleated sheet)
What happens in the 3rd phase of protein structure?
Tertiary: Protein structure forms
What are nucleic acids?
Acids involved in the production and synthesis of DNA and cell division
What forms nucleic acids?
Ribose/deoxyribose, phosphate, sugar (backbone)
Describe DNA
Double helix strand, hydrogen bonds formed between nitrogenous bases, 5’ to 3’
Describe RNA
Single strand, bonds with itself,
What is a eukaryotic cell?
Contains internal membranes that compartmentalize their functions, DNA is in nucleus
What is a prokaryotic cell?
Lacks a true nucleus, much simpler internal structure, dan concentrated in nucleoid
What is the cytoplasm?
The region between the nucleus and the plasma membrane
What is the plasma membrane/membrane of organelles?
Consists of a phospholipid bilayer, with proteins embedded/bobbing in it, carbs attached
What does it mean to be amphipathic?
Has water loving/hating regions ie: phospholipid
Where does transcription occur?
the nucleus
Where does translation occur?
The cytoplasm
What is the nuclear envelope?
Encloses the nucleus, composed of two membranes, one porous layer that allows proteins and RNA through
What is the nucleolus?
Where ribosomal RNA is synthesized
What are ribosomes?
Complexes made of ribosomal RNA and proteins: carry out protein synthesis
**remember that to synthesize protein uses mrna, rrna, and trna
What are the two types of ribosomes?
Free ribosomes and bound ribosomes *structurally identical
What are free ribosomes?
Suspended in cytosol, creates proteins for the cell
What are bound ribosomes?
Attached to the outside of endoplasmic reticulum and nuclear envelope, creates proteins for membrane and out of the cell
What is the endosymbiont theory?
Early prokaryotic cells that were absorbed by the cell ex: mitochondria: oxygen using non photosynthetic prokaryotic cell absorbed
What is the mitochondria?
Sites of cellular respiration, turns sugar into energy
What are chloroplasts?
Found in plants, photosynthesize, contain plastids and chloroplasts, contain a 3rd membrane: thylakoid membrane
What is a peroxisome?
Contains enzymes that produce H2O2
- break down harmful things, removes Hydrogen, and adds to oxygen
What is the endomembrane system?
Regulates protein traffic and performs metabolic functions
What forms the endomembrane system?
Nuclear envelope
The endoplasmic reticulum (rough/smooth)
The golgi apparatus
Lysosomes
Vesicles and vacuoles
Plasma membrane
What is the endoplasmic reticulum?
Network of membranous tubules and sacs called cisternae
What are the two kinds of ER?
Smooth and rough
What does the smooth ER do?
outer surface lacks ribosomes, functions in diverse metabolic processes
What does the rough ER do?
-Studded with ribosomes
- makes proteins to be secreted, and membrane proteins
How do proteins leave the ER?
Through transport vesicles from the rough er to the cis face of the Golgi apparatus
What is the Golgi apparatus?
The ‘shipping and receiving centre’, consists of flattened membranous sacs called cisternae, not physically connected, different enzymes that do different modifications