Biology Notes 2

Leenwenhoek

developed the first microscope

Robert Hooke

discovered that small things look like rooms and started calling them “cells” the name stuck. Given credit for the “discovery” of cells.

Schledidem and Schwann

are given credit for cell theory – all living organisms are made of cells.

Virchow

responsible for the theory of biogenesis – living cells must come from pre existing cells and do not come up on their own.

Germ Theory

infectious disease comes from microscopic agents called germs. You cannot “catch” a cold from being cold, it is a myth.

Lister

late 1800s developed just standard medical practice, sanitizing and changing bandaids.

Louis Pasteur

broth experiment supported biogenesis and germ theory

protoplasm

living part of the cell inside

plasma membrane

cells are bounded by this phospholipid (surfactant (both hydrophilic and hydrophobic)). Holds things together as well as regulates the passing of things in and out of the cell

Phospholipid

phosphate part is hydrophilic despite lipid part being hydrophobic so is a surfactant, as well as being amphipathic

amphipathic

hydrophobic and hydrophilic aspects (polar and nonpolar portions)-- what the phospholipid is

liposome

any bilayered sphere, water on inside and outside. Hydrophilic aspects face towards water while the hydrophobic aspect faces against water.

Permease

carrier molecule– acts as an enzyme but doesn’t carry out a chemical reaction, just moving things. (ase - enzyme)

diffusion

Particle moves through membrane by simple ___ net random movement of particles from high concentration to low concentration– naturally moves from high to low

osmosis

a special type of diffusion across a membrane for an area of low solute concentration to an area of high solute concentration. “Diffusion of water across a membrane.” Draws water OUT

Plasmolysis

death by osmosis, death of cells due to osmotic drying. Salt on slug or snail.

Isotonic

The same solute concentration on both sides of the membrane. Water moving in is balanced by water moving out– in equilibrium “happy”.

hypotonic

More solute inside the cell than outside the cell, absorbs water. Starfish are isotonically balanced by seawater so a hypotonic environment would kill them (tapwater). Cells will absorb the water because of the osmotic imbalance “Sucked dry”

hypertonic

having a higher osmotic pressure than a particular fluid. less solute outside of cell than inside; osmosis pulls water into cell; swells until bursting

selectively permeable (membrane)

a biological or synthetic barrier that permits some molecules or ions to pass through while preventing others

facilitated diffusion

(transport) high concentration to low concentration across a membrane using a carrier molecule.

rate of diffusion

how quickly molecules or particles move from an area of high concentration to an area of low concentration

active transport

to run against a concentration gradient you have to put in energy. Movement across membranes using a permease that requires energy.

endomembrane system

includes; nucleus, endoplasmic reticulum, Golgi body or apparatus, various structures like vacuoles and vesicles. Create a division of labor which increases efficiency, only in the eukaryotic cells

chloroplast and mitochondria 

in eukaryotes but separate from the endomembrane system 

nuclear membrane

what the nucleus is surrounded by— similar to plasma membrane but has 2 layers of bilayer that works different than just one layer 

prokaryote

simplest type of cell that we know of, extremely tiny and is mostly bacteria

eukaryote

advanced cells that have a endomembrane system that features a Golgi apparatus, vacuoles, vesticles, and a nucleus

transcription 

copying the code from DNA to RNA

translation

turning the mRNA to polypeptide

Post translational modification

where any globular proteins are folded, coming out the other end is → vesicle inside cytoplasm containing digestive enzymes

lysosomes

digestive enzymes, needed for an amoeba to digest food

peroxisomes

breaking down fatty acids and neutralizing harmful toxins, or merges with plasma membrane and release to outside secretory vesicles– called exocytosis

mitochondria

energy production “powerhouse” has 2 different membranes– outer membrane and inner membrane (that is highly folded to produce sheet like folds called cristae)

Endosymbiotic hypothesis

at one point the cell was a prokaryotic cell but has been adopted basically by the prokaryotic as one area. “Mitochondira has developed from an early prokaryotic cell”

chloroplast

similar to mitochondria with a single membrane, stacks (each coin is called a thylacoid) the chlorophyll is in the coins, performs photosynthesis

plasmo desmata

“Little membrane tunnels that connect the cells”

algae

2 flagellum with little branches, single chloroplast (for photosynthesis– containing green pigment chlorophyll), contains nucleus, area of pigment that detects light

nucleolus 

Extra dark spot inside the nucleus (made of RNA) where all of the RNA in the nucleus is.

chromatin 

(named after a type of stain used to see hard to see tiny organisms made of a base) – when you look closely looks like distinct structures that look like x’s

Rough ER

in the endoplasmic reticulum, contains ribosomes 

Smooth ER

part of endoplasmic reticulum that does not contain ribosomes, contains membrane instead; also makes proteins 

Golgi

series of sacks of the reticulum of the adjacent cell is shared

chromosomes 

carry the code for manufacture of a protein— the little x shaped things made of chromatin 

contractile vacuole

clear part of “aquatic” cells, regulates water content of the cells.

exocytosis

a process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane. Happens in contractile vacuole

osmoregulation

process of controlling water content for organisms living in fresh water.

flaggellum

a tube bounded by membrane, inside are a series of protein structures called microtubules

turgar pressure

pressure against the cell wall caused by the osmotic uptake of water.

pellicle

in a simpler (single-cell) animal cell there is a thin coating

endocytosis

taking particles in by engulfing — general umbrella term for phagocytosis and pintocytosis

phagocytosis

eating particles as food

pintocytosis

the formation of small vesicles. Primary purpose is to suck up liquid rather than solid particles, liquid

cillia

short flaggellum

basal body

Cells that have cilia have a structure that anchors it (same in plant cells w/ flagellum)

Cross section of this anchor structure is called a

centrioles

9 triplets of microtubules and lie outside nuclei of animal cells.

Involved in cell division, not in plant cells

tight junctions

"Sausage link” looking thing is plasma membrane. They are functionally stapled together by little proteins — way to connect multiple animal cells

desmosomes

Flat disk-like proteins in each cell that face each other, microproteins go through one to another and therefore hold them together loosely.

communicating junction 

plasma membrane of two adjacent cells has a protein plate between them, series of protein molecules form a tunnel through the two cells

chitin

euakryotic organisms like fungus have cell walls made of these instead of cellulose 

prophase

Nucleolus disappears and chromatin grows. The chromatin is coiling in on itself, getting thicker and thicker, until they look like a bow. Nuclear membrane breaks down and is absorbed into the smooth ER for later use. Microfilaments turn into a longitude looking thing called the “spindle apparatus” that begins the cytoskeleton of the structure. Chromosomes migrate to the equator of the spindle.

metaphase

The chromosomes migrate and attach to a spindle fiber by the centromere. “When the chromosomes are on the equator.”

anaphase

Centromeres (bow looking things) split and half of the chromosomes go into two different directions towards the poles.

telephase

The chromosomes make it to the poles and we have to “undo” prophase. New nuclear membrane forms over each new group of chromosomes. The spindle formed in prophase starts to break down. The chromosomes turn invisible and a nucleolus turns back into a normal cell. → turns into G1 (it started in G2).

cytokinesis

cell division that happens in the cell plate— happens in telaphase

interphase

if you can see a distinct nucleus and nucleolus— time. the cells spends not reproducing 

asters

the centrioles in the prophase explode

cleavage furrow

cytokinesis in animal cells, cells are “cleaved” apart until it is two

schizogony

nucleus divides into 2 each of those nuclei divide into 2 and so on, ending up with 8 nuclei. It then divides like cutting a pie, cytokinesis is DELAYED

homolugous pair

each chromosome has a matching chromosome,

diplpoid 

2 sets of chromosomes. Life cycle that needs reproduction needs to cut diploid into a haploid (one set)

haploid

one set of chromosomes

syngamy

For the haploid to get back to diploid it has to fuse with another haploid; this fusion is called

zygote 

the initial single cell formed when a sperm fertilizes an egg

mitosis 

1 division = 2 cells, this is chromosomal maintenance, happens in somatic cells (every cell thats not a sex cell. PMAT 

meiosis

1 → 4 cells, also feature homologous chromosomes in synapse. Chromosomal reduction, cutting the number of chromosomes in half, specifically for gametes (sex cells).

PMAT repeated twice.