Unit 2 Flashcards
What 3 observations make up the cell theory?
All organisms are made up of cells
The cell is the fundamental unit of life
Cells come from preexisting cells
Define cell
Group of organelles and molecules working together to perform a specific task and help the organisms maintain homeostasis
What are the 2 categories of cells
Prokaryotic and eukaryotic
Define metabolism
The set of chemical reactions in cells that build and break down macromolecules and harness energy
The two major types of prokaryotes are
Bacteria and archaea
What are the characteristics of prokaryotes that aren’t in eukaryotes?
What are the characteristics of eukaryotes that aren’t in prokaryotes
What are the shared characteristics of prokaryotes and eukaryotes
How big is a cell usually?
10 micrometers to 1 mm in range
What’s important about a cells size?
What’s a non membrane bound organelle?
Organelles that do not have their own membrane inside of the cell
What’s a membrane bound organelle
Organelles that have their own membrane inside of the cell
Why are membrane bound organelles important?
Why are membrane bound organelles important regarding the size of the inside of the cell?
How do prokaryotes and eukaryotes differ regarding their nucleus?
Prokaryotes lack a nucleus and extensive internal membrane and rather have their DNA in the shape of a circle found in the nucleoid. Prokaryotes also often contain smaller circles of DNA known as plasmids that can transferred through threadlike structures called pili
Eukaryotes evolved ___ compared to prokaryotes in the history of life
Later
What are the two ways to look at the endosymbiotic theory?
What was the mutual benefit of the prokaryotes and eukaryotes in the endosymbiotic theory?
Ancestral prokaryotic = would become eukaryote through engulfing proto prokaryote
What 4 pieces of evidence suggest that mitochondria and chloroplasts were once free living bacteria?
- Structural evidence
Chloroplasts and Cyanobacteria have stacks of membrane - DNA evidence
Similar genes/DNA sequences - Reproduction
Both do binary fission - chloroplasts and mitochondria have a double membrane suggesting that when they were engulfed as a proto prokaryote they took some of the membrane off the ancestral prokaryote and it formed around their 1st membrane
The evidence that suggests of mitochondria and chloroplasts were once free living organism promotes that chloroplasts came from ____ and mitochondria came ____
Cyanobacteria (archaea)
Proto bacteria (bacteria)
What are all non membrane bound organelles
Cell membrane, cell wall, Ribosomes, cytoplasm, cytoskeleton, centriole and spindle fibers, flagella
(8)
What is the cell membrane?
What is the cell wall?
True or false: Ribosomes are only found in animals
False
they are found in all living organisms
What are ribosomes composed of?
Proteins and Ribosomal RNA (rRNA)
What do ribosomes do?
Read messenger RNA (mRNA) to synthesize proteins
Where can ribosomes be found?
Attached to Rough ER or free floating in the cytoplasm
What’s the cytoplasm? What does it do and what’s it the site of?
What’s the cytoskeleton? What does it do and what’s its parts?
What is the cytosol?
The fluid part of the cytoplasm
What do the centriole and spindle fibers do?
What’s flagella and cilia?
Name all membrane bound organelles
MiNuSERNuRERGaLyPeVaCh
Name all organelles in the endomembrane system
NEVERGALCM
The endoplasmic reticulum is continuous with the ____
Outer memebrane of the nuclear envelope
What’s the nucleus and what happens there?
What’s the nucleolus and what happens there?
What happens at the smooth ER
Where is the rough er and what does it do
What does the Golgi apparatus do
How does the Golgi apparatus process proteins and lipids. What are they called afterward and what does each one do
What is the order of protein secretion from the cell
What do peroxisomes do
What do lysosomes do?
What’s a vacuole and what does it do
What’s different about mitochondrial membranes
What’s different about chloroplast structure?
What type of cells are cytoskeletons present. How do cytoskeletons affect the structure in eukaryotes
All cells
The cell wall in plants are made of ___ to help maintain ___ and present in _ _ _ _ _
Cellulose
Cell structure
Plants, algae, fungi, archaea, bacteria
Vacuole are ___ organelles in plant cells that help maintain __
Conspicuous
Turgor pressure
Define surface area
Measure of the total surface of a three dimensional object
Define volume
Measure of the total space occupied by a three dimensional object
What do cells need a large surface area to volume ratio?
How do projections effect a cell
The rate of diffusions is the ___ regardless cell size
Same
As objects get bigger, surface area to volume ratio ___
Decreases
True or false: surface area increases more slowly than volume as a object gets larger
True
Diffusion is ____ and only effective over ___ distances
What limits the size of eukaryotes?
Diffusion
Diffusion is the process by which molecules spread from areas of high concentration to areas of low concentration.
Where are active cells located in some multicellular organisms?
Along the periphery close to the source of nutrients and other key molecules
This positioning allows for efficient nutrient uptake.
What organ in some multicellular organisms has a large surface area to facilitate diffusion?
Lungs
The structure of lungs enhances gas exchange due to their large surface area and thin walls.
True or False: Diffusion allows for the transport of nutrients in multicellular organisms.
True
Diffusion is crucial for delivering nutrients to cells in multicellular organisms.
Fill in the blank: Some multicellular organisms have _______ with large surface areas and thin walls that allow for diffusion.
organs
Organs like lungs are specialized for efficient gas exchange.
What is bulk flow
What does bulk flow and what does it circumvent?
What is the cell membrane and what is it composed of?
Why is the cell membrane called a fluid mosaic
Because it is made of many components that can move laterally in the membrane
Membranes have selective permeability this means what?
Why do membranes only allow small non polar molecules diffuse freely through the spaces between the phospholipids?
What’s the structure of a phospholipid
What are the components of the cell membrane? What do each of them do?
Species that live in cold environments will have a higher percent of ___ fatty acids. Why
To increase membrane fluidity
What are 3 types of proteins that are part of the cell membrane and fine them
What are channel proteins
What are receptor proteins
What’s an Aquaporin
Channel proteins that allow water to pass through more easily
What’s a carrier protein
Integral protein that transports large or charged molecules across the membrane due to conformational change
What’s importance of cell transport
What’s the concentration gradient and how does it generally move molecules?
Difference in concentration of molecules across a space
molecules moving with the concentration gradient moves from areas of high concentration to areas of low concentration
Atoms/molecules have inherit energy that causes them to vibrate and move ___
Randomly
Net movement refers to ____. These molecules generally follow the ____
What is cell transport and the two types?
What is passive transport and what does it require for molecules to pass through
What is active transport and what does it require for molecules to pass through
What is dynamic equilibrium in regards to diffusion?
What are the 3 different types of passive transport
What is simple diffusion?
What is facilitated diffusion?
Diffusion is not affected by the number of ______
Solutes
What type of molecules require channel proteins to cross the membrane?
Large, polar, and charged molecules
These molecules cannot easily pass through the hydrophobic core of the membrane.
What is the role of channel proteins in cellular transport?
Facilitate the crossing of dense hydrophobic core of the membrane by specific molecules
Channel proteins are integral membrane proteins that assist in the transport of substances.
Facilitated diffusion and Active Transport are both examples of _______.
[facilitated transport]
These processes help in the movement of substances across the cell membrane.
True or False: Facilitated diffusion requires energy input.
False
Facilitated diffusion is a passive process.
What is the primary difference between facilitated diffusion and active transport?
Active transport requires energy, while facilitated diffusion does not
Active transport moves substances against their concentration gradient.
Large quantities of water require the help of ___ (which are an example of ___) to pass through the membrane since water is ____ and _____. Small quantities of ____ can still osmose through though
Aquaporins
Facilitated diffusion
Polar
hydrophilic
Water
The ____ is an example of ____ and is responsible for the ____ of Na+ and K+ ions across the membranes of neurons. This allows for maintenance of _____ which is required for ____ in neurons
Sodium potassium pump
Active transport
Concentration gradient
Membrane potential
Electrochemical signaling
Define membrane potential
Difference in charge between the inside and outside of the cell. It helps the cell send signals.
Secondary active transport uses the energy stored in an ____ to move another molecule against its gradient
Electrochemical gradient
What is the membrane potential a consequence of?
Ion transportation
Membrane potential arises due to the movement of ions across the membrane.
What creates the membrane potential?
Separation of charge across the membrane
This separation leads to a difference in electrical charge, analogous to a battery.
How does the membrane function in relation to electrical potential energy?
Acts like a battery, storing electrical potential energy
The membrane’s ability to store energy is crucial for cellular functions.
What happens when ions change concentrations on both sides of the membrane?
The membrane can become polarized and fire an electrical signal
This polarization is essential for processes such as nerve impulse transmission.
What is endocytosis and what does it require
And the input of metabolic energy(ATP) to occur
What is exocytosis and what does it require?
And the input of metabolic energy(ATP) to occur
Exocytosis and endocytosis are example of ___ transport
Active
When does phagocytosis occur? It’s an example of __cytosis
When a cell takes in large substances
Endo
When does pinocytosis occur? It’s an example of __cytosis
When a cell takes in small substances
Endo
What is osmoregulation?
How an organism maintains the balance of water and dissolved materials in its body regardless of environmental conditions.
How is osmoregulation maintained?
Through osmosis and adjusting water potential across the cell membrane.
What happens to cells that do not properly maintain osmoregulation?
They will die; widespread failure can kill organisms.
Osmosis is the ___ from ___ concentration to ____ concentration
What does tonicity describe?
How much solute is dissolved in the solvent
Tonicity is crucial for understanding the movement of water across membranes.
What are the two components of a solution in relation to tonicity?
- Solute: Substance being dissolved
- Solvent: Substance doing the dissolving
Understanding these components is essential for grasping the concept of tonicity.
The tonicity of solutions on either side of the membrane will predict where the _______ will go.
water
What determines the tonicity of a solution a cell is in?
The comparison of the extracellular solute concentration to the intracellular solute concentration
Tonicity affects the movement of water across the cell membrane.
What is a hypotonic solution?
A solution where the extracellular solute concentration is lower than the intracellular solute concentration
Cells in a hypotonic solution may swell as water enters.
What is a hypertonic solution?
A solution where the extracellular solute concentration is higher than the intracellular solute concentration
Cells in a hypertonic solution may shrink as water exits.
What is an isotonic solution?
A solution where the extracellular solute concentration is equal to the intracellular solute concentration
Cells in an isotonic solution maintain their shape and volume.
Fill in the blank: A _______ solution causes a cell to swell due to lower extracellular solute concentration.
hypotonic
Fill in the blank: A _______ solution causes a cell to shrink due to higher extracellular solute concentration.
hypertonic
True or False: An isotonic solution causes net movement of water into or out of the cell.
False
In an isotonic solution, there is no net movement of water.
What is osmolarity?
A measure of the total concentration of solute particles in a solution, regardless of whether they cross the membrane.
What does tonicity do?
Predicts water movement across the membrane, focusing on the concentration of solutes that can’t cross the membrane.
True or False: Osmolarity considers only solutes that cannot cross the membrane.
False
Fill in the blank: Tonicity focuses on the concentration of solutes that _______ cross the membrane.
can’t
What does osmolarity measure?
Total concentration of solute particles in a solution.
What does tonicity predict?
Water movement across the membrane.
How does water move in terms of concentration?
Water moves from high concentration of water to low concentration of water.
This principle is essential in understanding osmosis.
What is the relationship between water potential and water movement?
Water moves from areas of high water potential to areas of low water potential.
Water potential is a measure of the potential energy in water, influencing its movement.
From where to where does water move based on solute concentration?
Water moves from areas of low solute concentration to areas of high solute concentration.
This process is crucial in biological systems for maintaining cell turgor pressure.
What is the movement of water in relation to osmolarity?
Water moves from areas of low osmolarity to areas of high osmolarity.
Osmolarity refers to the concentration of solute particles in a solution.
What must be determined to understand water movement relative to a cell?
You need to figure out if the concentration of water is higher inside or outside of the cell.
This assessment helps predict the direction of water flow during osmosis.
What is the process through which water moves in plants?
Osmosis
What structures must water move through in plant cells?
Cell wall and cell membrane
Where is water stored in plant cells?
In large vacuoles
What is turgor pressure?
The pressure the water exerts back on the cell wall
What does the cell wall exert back on the cell?
Force
What does turgor pressure help maintain in plant cells?
The shape of the cell
How does the cell wall affect water intake in plant cells?
It limits how much water can get into the cell
What is one function of the cell wall in plant cells?
Provides structure
Hypertonic, isotonic, and hypotonic solution by plants
What are osmoconformers?
Osmoconformers are able to change their internal osmotic concentration with change in external environment.
Examples include marine molluscs and sharks.
What is the primary characteristic of osmoregulators?
Osmoregulators maintain their internal osmotic concentration irrespective of their external osmotic environment.
An example is otters.
Fill in the blank: _______ are organisms that can change their internal osmotic concentration based on external conditions.
[Osmoconformers]
True or False: Osmoregulators have the ability to change their internal osmotic concentration with changes in the external environment.
False
