Unit 2 - Cell Structure and Function Flashcards
What are the two types of cells?
prokaryotes and eukaryotes
What are examples of prokaryotes?
Bacteria and Archaea
What are archaes also known as
extremophiles
What are examples of eukaryotes?
plants, fungi, animals, protists
What are characteristics of prokaryotes?
- they have no organelles
- DNA is free floating inside the cytoplasm
- DNA is circular in it’s shape
- DNA is found in the nucleus
- has a plasmid
- cell wall is make up of Peptidoglycans
Peptidoglycans
protein + carbs (amino acids + sugars)
What are characteristics of eukaryotes?
- has membrane bound organelles
- DNA is found inside of the nucleus
- DNA is linear in its shape
- DNA is found in the nucleus
- contains a mitochondria
- cells walls (for plants its cellulose and fungi its chitin)
What is the shape of DNA in prokaryotes?
circular
What is the shape of DNA in eukaryotes?
linear
What are some common structures between Eukaryotic cells and prokaryotic cells?
- ribosomes
- cytoplasm
- plasma membrane
Cytoplasm
jelly-like substance that fills the interior of a cell
Cytosol
The fluid portion of the cytoplasm
Plasma membrane
outer boundary of a cell (cell membrane )
Nucleus
- contains DNA
- surrounded by a nuclear envelope called pores
Endoplasmic Reticulum
- intracellular transport
- contains the Rough ER and the Smooth ER
Rough ER
has ribosomes and these ribosomes are going to make proteins for the cell membrane or to be taken out of the cell
Smooth ER
synthesises lipids (steroids) so basically fats like estrogen, testosterone/detoxification - doesn’t have ribosomes cause it’s smooth
Ribosomes
- make proteins (protein synthesis)
- rRNA - a type of RNA that helps make up ribosomes
rRNA
a type of RNA that helps make up ribosomes
Golgi Apparatus
- sort and modify proteins and other macromolecules
- tertiary structure
- receive and makes vessicles
- export proteins + other macromolecules out of the cell or to the cell membrane
- make the lysosomes
how do lysosomes work
lysosomes are made by the Golgi and they eventually breakdown and recycle waste inside the cell
Endomembrane system
- the DNA in the nucleus is copied into a smaller version called mRNA and then goes to the R.E.R
- the ribosomes on R.E.R read the instructions from the mRNA and synthesizes proteins
- proteins are taken to the golgi by vesicles and finalized by the golgi to leave out of the cell
lysosome
- digestive organelle
- hydrolysis on the protein
- autophagy - destroys the worn out organelles
autophagy
- destroys the worn out organelles; process performed by the lysosomes
Apoptosis
a process of programmed cell death that is essential for maintaining healthy tissues in multicellular organisms
Mitochondria
- cellular respiration which makes ATP
What is ATP made of?
a nitrogenous base (adenine) , a sugar (ribose), and three phosphate groups
Endosymbiotic Theory
some of the organelles in eukaryotic cells, specifically mitochondria and chloroplasts, were once free-living bacteria that were taken in by a larger cell. Instead of being digested, these bacteria formed a symbiotic relationship with the host cell.
Chloroplasts
- photosynthesis - light turns into sugar
- endosymbiotic cell - algae ate a chloroplast
Vacuole
- stores food, water, and waste
- tonoplast - covers vacuole
cytoskeleton
- network of protein fibers in both plant and animal cells that provides structural support and enables the cell to move and change shape.
What are the 3 main components of the cytoskeleton?
- microtubules
- intermediate filaments
- microfilaments (flagella + cillia)
Peroxisome
breaks down peroxide
Centrioles
cell reproduction (animal cells)
Advantages of Organelles
- larger sized cells
- compartmentalize reactions
- more metabolic reactions
- increase complexity of an organism
Surface area to volume ratio
amount of surface area in a given volume
Why is a larger surface area to volume a good thing for cells/
because nutrients and waste will diffuse faster and more efficently
How do cells increase surface area?
Folding of the Cell Membrane: Cells often fold or extend parts of their membrane to create more surface area.
So, while cilia don’t exactly add more space, they help move things around
What are structural adaptations that increase surface area to volume ratio
- root hairs (plants)
- absorption of nutrients and water
Cell Membrane
- plasma membrane
- regulates what comes in and out of the cell
- found in both types of cells
What does a cell membrane regulate based off on
regulates based on polarity, charge, and size
Why is it called a bilayer?
- 2 sets of hydrophilic heads/hydrophobic tails in order of have water inside
Fluid Mosaic Model
- cell membrane is fluid it can change shape without breaking and it has many components to it
A high concentration of saturated fats means
its rigid and stiff
A high concentration of unsaturated fatty acids means its
fluid
What kinds of molecules can pass through a non-polar region with no resistance?
- non polar no charge
- Carbon Dioxide and Oxygen can pass freely through the membrane
What kind of molecules cannot pass through a non polar region with no resistance?
- polar large and charged
Cell Membrane Components
- cholestrol: fluditiy of membrane
- integral protein - transport (ex. aquaporins)
- peripheral proteins - cell signaling on the outsides
- glycoprotein/glycolipid - cell recognition
Simple Diffusion
- moving molecules go from high concentration to low concentration so they can easily passs through the cell membrane without any help so no energy is required (ex. lipids like steriods and O2)
What type of transport is simple diffusion?
passive transport
Facilitated Diffusion
using proteins to move molecules from high to low concentration still without any energy requires - integral proteins (charged molecules, polar molecules, CFTR)
What type of transport is facilitated diffusion?
passive transport
Active Transport
molecules move from low concentration to high concentration and uses ATP (ex. sodium potassium pump
endocytosis
brings large molecules into the cell using a vesicle to bring the molecules in
pinocytosis
cell drinking; bringing in liquids
phagocytosis
cell eating
exocytosis
removing large molecules using a vesicle
Tonicity
the ability of water to move into solutions with high concentrations of solute
Isotonic
equal amounts of solute and water in solution and in a cell (no net movement of water; water just moves in equal parts)
Hypotonic
- more water in solution and less solute in solution
- water will move into the cell
- cells could lyse
cytolysis
cells burst in an animal cell in a hypotonic solution
Turgid
in plant cells, the cell membrane pushes aganist the cell wall in a hypotonic solution
Hypertonic
- more solute in solution and less water in solution
- water will leave cell
Plasmolysis
cell membrane shrinks bc it loses water in a plant cell in a hypertonic solution
Crenation
shrivel up the cell bc it loses water in an animal cell in a hypertonic solution
Osmoregulation
the process by which organisms maintain the balance of water and solutes in their bodies, ensuring that their cells function properly
Freshwater Organisms
Freshwater fish live in a hypotonic environment (water has a lower solute concentration than the fish’s body fluids), causing water to constantly enter their bodies.
Osmoregulation Strategy:
They produce large amounts of dilute urine to expel excess water.
Their gills actively absorb salts from the water to replace the lost solutes.
Paramecium
Paramecium have contractile vacuoles that collect excess water and expel it out of the cell. This helps maintain internal osmotic pressure.
Salt Water Organisms
Marine fish live in a hypertonic environment (water has a higher solute concentration than their body fluids), causing them to lose water to the surrounding sea.
Osmoregulation Strategy:
They drink large amounts of seawater to compensate for water loss.
Their gills excrete excess salts, actively transporting sodium and chloride ions out of their bodies.
ADH
antidiuretic hormone that tells the kidneys to make aquaporins to reabsorb H2O
Diuertic
make you urine
What is water potential?
a measure of how water moves in a solution (high to low)
What are two variables that affect osmosis and the movement of water?
pressure and solute concentration
Pressure potential
- physical force
- open container means that it’s implied that the pressure potential is 0
Solute Potential
how much solute is in a solution
How does solute affect water?
water is attracted to the solute
the solute potential of pure water or distilled water is
0
Why is the solute potential of water 0 and can it be positive numbers?
when you dissolve solutes (like salt or sugar) in water, the solute potential becomes negative because the presence of solute particles decreases the water’s ability to move (
What does a noncompetitive inhibitor do?
binds to a recepetor reducing the effectiveness of the binding
-15% change
hypertonic
