Unit 2 - Cell Structure and Function

eukaryotes

multi-cellular

prokaryotes

single-cellular

prokaryote vs eukaryote DNA

prokaryote:

• single chromosome

• circular molecule in ring form

eukaryote:

• linear molecule

• contain telomeres

differentiation (what type of cell is capable of this)

division into more specific cells (stem cells are able to do this)

telomeres

protective caps at the end of chromosomes

in stem cells ________ regenerate shortening with every division eventually leading to apoptosis

telomeres

apoptosis

cell death

flagella sizes

flagella (longest and smallest amount) → pilus (medium length and medium amount) → fimbria (shortest and largest amount)

Robert Hooke

discovered cells looking at dead plant cells (cell walls/cellulose)

modern name for cell membrane

fluid mosaic model

all cells come from _____ _______.

pre-existing cells

a cell is a ______ and _______ unit of life.

structural/functional

what protects nucleus and DNA and what is in it that allows DNA to leave

nuclear envelope that has holes/pores

plasmid

one circular chromosome separate from main that replicates separately

bacteria have _________ and _________ and _________ (sometimes).

cell wall/membrane/capsule

golgi apparatus

processes and packages proteins and lipids by putting together more complex molecules from simpler ones and placing them in vesicles that are released to new locations

lysosomes

vesicles with hydrolitic enzymes that aid in hydrolisis by breaking down waste and complex molecules or antigens, they work best in acidic environments

excytosis

the process of packaging and removing waste

peroxisomes

break down lipids and release hydrogen peroxide as a by-product

microtubules

hollow proteins in secondary structure that support the cell structure (part of cytoskeleton)

microfilament

part of cytoskeleton and provide support for the cell from the inside made of double chain of actin. myosin moves microfilaments

mitochondria

has two membranes and creates energy through ATP synthesis and contains its own circular DNA because it is preliving prokaryotes engulfed by the eukaryotic cell (DNA from mother)

smooth ER

• enzymes aid in lipid synthesis including hormones

• Enzymes aid in drug detoxification by adding hydroxyl groups to them making them soluble

• Stores calcium and releases it triggering certain responses

rough ER

protein synthesis specifically membrane proteins that act as receptors, enzymes, channels, etc and membrane synthesis by adding phopholipids to own membrane and transferring it

chloroplast

photosynthesis(energy synthesis) in plant cells that contains its own circularly shaped DNA likely also from being a past prokaryotic cell engulfed by the eukaryotic cell

enzymes

biological catalysts that speed up chemical reactions by lowering the activation energy

substrate

molecule that attaches to active site of enzyme

enzyme name endings

in digestive system “ise“ but otherwise “ase“

activation energy

initial energy required to start a reaction

conformational shape

unique 3D shape of enzyme

denaturization

changes to conformational shape of enzyme

what two factors cause denaturization

pH and temperature

optimum pH and temperature

range of temperature and pH during which reactions occur the quickest

why higher temperature causes quicker reactions flow chart

increase in temperature → faster molecules → more collision → more interaction → faster process

why pH change causes change in reaction efficiency flow chart

pH fluctuation → disrupts hydrogen bonds in protein structure → enzyme denatures

why does reaction efficiency platoe at a certain point as substrate levels increase

product takes up space which slows down reaction through less interaction of substrate with enzyme

competitive inhibitors

molecules that bind to activation sites instead of substrate

non-competitive/allosteric inhibitors

bind to allosteric sites changing shape of enzyme preventing substrate from binding

sunlight energy flow chart in plant cells

sun → chloroplast → photosynthesis → mitochondria → cell respiration

every energy transfer _______ universe disorder

increases

sequential reaction

products of one reaction used as reactant of another, when one is removed it stops the reaction but may be replaced by increasing the amount of previous substrate

scanning electron microscopy

3D images of organelles on or in cells

transmission electron microscopy

2D image of thin section of cell showing layers

smallest organelles isolated in cell fractionation and what is it

the blending of cells and centrifugation to collect different fractions, ribosomes smallest

domains with prokaryotic cells

bacteria and archaea

amphipathic

a molecule that is both hydrophilic and hydrophobic

glycoprotein

protein with a carbohydrate attached

glycolipid

lipid with a carbohydrate attached

when _______ is used a protein is a _______ protein

energy/transport

surface area to volume ratio in cells

n²:n³

nuclear lamina

net of protein filaments that support nuclear envelop

nuclear matrix

fibers that extend through the nuclear interior

chromatin

make up chromosomes and are made of proteins and DNA

nucleoli

visible in nondividing nuclei and are where ribosomal RNA in synthesized and proteins are assembled with rRNA

ribosomes

carry out proteins synthesis and are composed of rRNA and proteins

free ribosomes

enzymes

bound ribosomes

export, membrane insertion, and lysosomes

structures in endomembrane system

nuclear envelope, endoplasmic reticulum, golgi apparatus, lysososmes, vacuoles, plasma membrane

detoxification

enzymes add hydroxyl group to harmful molecule which makes them soluble, if there is a lot the reaction occur more which means the overall breakdown of harmful molecules will increase

what does the rough ER do with glycoproteins

released in membranes of vesicles and transported to other cell parts

golgi apparatus description with proper terms

As vesicles approach the Golgi apparatus they bind to it to form new cis golgi cisternae. The cisternae more to the trans face forming vesicles and leaving the Golgi to other parts of the cell and coming back with other proteins repeating the process.

autophagy

damaged organelle or cytosol is surrounded by membrane and fuses to lysosome that dismatles and returns to cytosol

food vacuoles

carries enzymes and macromolecules for digestion

contractile vacuoles

pumps excess water out of cell

central vacuoles in plants

smaller vacuoles that transport solutes and are selective

protein secretion flow chart

synthesis in rough ER → transport vesicles → golgi apparatus cis face → forms cisterna moves across → vesicles formed and depart from trans face

cytoskeleton

network of fibers that extends through cytoplasm supporting cell structure, cellular movement, and regulating biochemical processes

intermiduate filaments

part of cytoskeleton

centrosome and centrioles

microtubule organization center where microtubules are assembled

cilia vs. flagella

Cilia are more rigid protrusions that lean back and forth while flagella are more flaccid proturisions that undulate. While both aaid in cellular movement the way they do so is different.

dyneins

proteins that move cilia by energy from ATP the arms from one dynein attach to another and pull sliding past each other causing the cilia to bend left and right.

primary cell wall

thin flexible wall secreted first by plant cell

middle lamella

secondary layer of cell wall made of pectin

primary cell wall

rigid wall on the inside

extracellular matrix

network of proteins and molecules that provide structural support for cells

passive cell transport flow chart

passive → no ATP → diffusion (non membrane required) and facilitated osmosis (membrane required)

active cell transport flow chart

membrane always required → individual molecules or bulk

osmosis

H2O movement (requires membrane)

tonicity

solution cause cell to swell or shrink

hypotonic

H2O enters cell when more H2O outside and causes cell to burst

cytolysis

cell bursting

hypertonic

H2O leaves