LECTURE 02 Flashcards
What is the major difference between plants and animals at the cellular level
plants: cell wall, vacuole, chloroplast
Animals: Cholesterol
What is the cell membrane made of
Made up of lipids, protein and carbohydrates
What is the plasma membrane
a selective barrier that controls the movement of molecules from the inside and outside of the cell
What is the endomembrane system
A system of membranes that include the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, vesicles, and plasma membrane.
What is the mitochondria/chloroplast
organelles used to harness energy and evolved from free-living prokaryotes
What are the three main things in cell theory
All organisms are made of cells. The cell is the fundamental unit of life.
In general, cells come from pre-existing cells.
What is the number of cells proportional to
the number of cells increase proportional to the size of the organism
What can the human eye see up to in terms of cell size
We can see up to 100 um and can’t see most plant/animal cells as we need a microscope
What is the phospholipid
The major lipid in the membrane
Why are phospholipids amphipathic
they have both a hydrophilic head and hydrophobic tail
What happens when the head of a phospholipid is large and bulky and only has one tail
They form Micelle
What happens when the head of a phospholipid is small and has two tails
they form the bilayer
What structure can the bilayer form
it forms an enclosed structure called the liposome
What is cholesterol and how does it work
an important component in the animal cell that influences membrane fluidity by forming strong interactions with phospholipids by acting as a buffer
What happens at high temps for cholesterol
they affect the tail and reduce fluidity
what happens at low temps for cholesterol
they prevent lipids from packing too tight together
What is the receptor for
they allow the cell to receive signals from the environment
What do enzymes do
they catalyze chemical reactions
What is the anchor for
they attach to other protein to help maintain cell structure/shape
What is a integral protein
protein that are permanently on the cell membrane (can’t be removed)
What is a peripheral membrane protein
protein that are temporarily on the lipid-bilayer or integral protein
How to peripheral membrane protein stay on other protein
Using weak non-covalent interactions
What do transporter do and what type of protein is it
they have the important function of moving ions/molecules across the membrane and they are integral proteins
How does the plasma membrane determine what moves across it
The plasma membrane is selective permeable (selects what moves across it)
What is the simplest movement across the membrane
Passive transport
How does passive transport work
It works through diffusion which is the movement of molecules from high concentration to low concentration the opposite can occur. No energy required
What it the process for moving large molecules across the plasma membrane
Facilitated diffusion
How does facilitated diffusion work
it works through proteins called channels and carriers which help move across the plasma membrane
What is the process name for diffusion of water
Osmosis
What are the four types of osmosis
Hypertonic- water moves from cell to outside
Isotonic - outside and inside have the same concentration
Hypotonic- water moves from outside to inside cell
very hypotonic - too much water moves inside cell and cell bursts
Why does the cell wall not burst during osmosis
the cell wall can’t burst as it can take in a lot of water
What is the force exerted by water against the cell wall
turgor pressure
What is active transport
transport where it moves from low to high concentration and needs energy from ATP
What are the two types of active transport
primary and secondary active transport
What occurs in primary active transport (how does is use energy)
transport of sodium and potassium against concentration gradient.
Uses energy directly
What occurs in secondary active transport
primary active transport pumps protein across cell membrane and creates a proton concentration -> antiporters use protons to move molecules against gradient
What is the process of exocytosis
vesicles are budded off of the endomembrane system and fuses with the membrane and gives content from the membrane to extracellular space
What is the nucleus
stores cell dna
Nuclear envelope
it defines the boundary’s of the nucleus
Nuclear pores
They help nucleus communicate with cells
What is Er
Its a large organelle that produces lipid/protein for uses inside/outside the cell
What is the rough Er
associated with ribosomes it synthesizes proteins using the ribosomes
What is the smooth Er
it has no ribosomes and used for lipid synthesis
What does the Golgi apparatus do
modifies protein/lipids produced in Er and sorts them as they go to final destination
What does the lysosomes do
they are relied on for protein, lipid, carbohydrates, and acid degradation
mitochondria/chloroplast
can duplicated themselves
believed to be bacteria/prokaryote that was captured by eukaryote (lived in cells)
