Biology chapter 4 McGraw Hill

cell

smallest unit of living matter

cell theory

1. All organisms are composed of cells
2. Cells are the basic units of structure and function in organisms
3. Cells come only from preexisting cells because cells are self reproducing

Created by Schleiden, Schwann, and Virchow

surface area to volume ratio

dividing a large cube into smaller cubes provides more surface area overall
reason why cells are as small as they are

Prokaryotic cells

cells that lack a membrane bound nucleus

Eukaryotic Cells

Cells that have a nucleus

bacillus

rod shaped bacterium

coccus

spherical shaped bacterium

spirilla

long rods twisted into spirals
rigid

spirochetes

long rods twisted into spirals
flexible

cell envelope

includes the plasma membrane and cell wall

plasma membrane

phospholipid bilayer with embedded proteins

ribosomes

tiny structures that use dna to perform protein synthesis

cyanobacteria

bacteria that can perform photosynthesis

thylakoids

internal membranes where chlorophyll and other pigments absorb solar energy to produce carbohydrates

flagella

A long appendage used for mobility of a cell

Fimbriae

small bristlelike fibers that sprout from the surface of a cell
used to attach a prokaryote to a surface

Conjugation pili

rigid tubular structures used by prokaryotes to pass DNA from cell to cell

organelles

membrane bound compartments
distinguish eukaryotes from prokaryotes

endosymbiotic theory

theory that the mitochondria and chloroplasts were prokaryotes taken up by larger cells

transport vesicles

membranous sacs that enclose molecules and separate them from the cytoplasm
use the cytoskeleton to move around

cytoskeleton

network of protein fibers
maintains the cell shape and assists with cell movement

nucleus

contains genetic information that is passed on from cell to cell
specifies the information used by ribosomes to perform protein synthesis
command center of the cell

nucleoplasm

semifluid matrix within the nucleus

chromatin

combination of proteins and nucleic acids
network of strands that are compressed into chromosomes

chromosomes

carry genetic information
compressed form of dna

genes

basic units of heredity

nucleolus

dark region of chromatin where rRNA joins with proteins to form subunits of ribosomes

nuclear envelope

double membrane that separates the nucleus from the cytoplasm

nuclear pores

tiny pores in the nuclear envelope that allow ribosomal subunits and mRNA to pass through

polyribosomes

groups of ribosomes

endomembrane system

consists of the
nuclear envelope
endoplasmic reticulum
several vesicles

endoplasmic reticulum

organelle with a complicated system of membranous channels and saccules (flattened vesicles)

Rough ER

studded with ribosomes
Right against the nucleus
proteins fold in this organelle
contains enzymes that can add sugar to protein chains

Smooth ER

Touches the Rough ER
does not have attached ribosomes
helps produce lipids

Golgi apparatus

consists of a stack of 3 to 20 slightly curved and flattened saccules
inner side is the cis face
outer side is the trans face
packages proteins into vesicles for exocytosis

Lysosome

membrane bound vesicles with digestive enzymes
breaks down substances and worn out cell parts

peroxisome

membrane bound vesicles that enclose enzymes involved with breaking down fatty acids
contains catalase to neutralize a harmful byproduct of its reactions, h2o2

vacuoles

membrane bound organelles used to expel waste and store macromolecules

chloroplasts

organelles that use solar energy to synthesize carbohydrates

photosynthesis equation

solar energy + carbon dioxide + water -> carbonhydrate + oxygen

mitochondria

organelles that perform celluar respiration to break down carbohydrates and create atp

celluar respiration equation

carbohydrate + oxygen -> carbon dioxide + water + energy

stroma

semifluid in a chloroplast

granum

stack of thylakoids

plastid

plant organelles surrounded by a double membrane

cristae

membrane in a mitochondria that increase surface area

semifluid matrix

contains mitochondrial dna and ribosomes

actin filaments

long, extremely thin, flexible fibers that occur in bundles or meshlike networks
contains two chains of globular actin monomers twister around each other in a helical manner

intermediate filament

intermediate in size between actin filaments and microtubules
form a ropeike assembly of fibrous polypeptides

microtubules

small hollow cylinders made of a globular protein called tubulin

centrosome

an organelle that serves as the microtubule organizing center
lies near the nucleus

centriole

short cylinders with a 9 + 0 pattern of microtubule triplets
replicate at right angles to each other before a cell divides

cilia

hairlike parts of a cell used for movement

signal peptide

It is the starting sequence of amino acids that determines whether or not the protein will go to the rough ER because it binds to the SRP, which binds to the receptor on the ER

central dogma of molecular biology

DNA -> mRNA -> protein