Unit 2 - Cell Structure, Function, and Energy Flashcards
The discovery of the cell
Robert Hooke used an early compound
microscope to look at a nonliving slice
of cork.
He noticed that the cork was made of tiny
empty chambers “cells”
Anton van Leeuwenhoek observed
pond water and discovered many tiny
living organisms
Cells are the basic units of life.
Matthias Schleiden concluded that all
plants are made of cells.
Theodor Schwann stated all animal
cells are made of cells.
Rudulf Virchow stated all new cells are
produced from existing cells.
The cell theory
All living things are made up of cells.
Cells are the basic units of structure and
function in living things.
New cells are produced from existing cells.
Prokaryotes and eukaryotes
All cells contain DNA
All cells are surrounded by a thin flexible barrier - cell membrane (AKA plasma membrane).
Cells fall into two categories.
Depends on presence of nucleus - large membrane enclosed structure containing DNA.
- Prokaryotes: cells without a nucleus.
- Eukaryotes: cells with a nucleus.
Prokaryotes
Smaller and less complex (simpler)
than eukaryotic cells.
Do not separate their genetic material
within a nucleus.
DNA is circular plasmid
Grow, reproduce, respond to environment.
Ex. bacteria
Eukaryotes
Larger and more complex than
prokaryotic cells
Contain dozens of structures and
internal membranes
Highly specialized
Nucleus separates genetic material
from the rest of the cell
Ex. animal cells, plant cells and fungi cells
Eukaryotic cell structures
Structures within a eukaryotic
cell that perform important
cellular functions are known as
organelles.
Cell biologists divide the
eukaryotic cell into two major
parts: the nucleus and the
cytoplasm.
The cytoplasm is the portion of
the cell outside the nucleus.
Function of the nucleus
The nucleus is the control
center of the cell
Control’s cellular activity
The nucleus contain nearly all
the cell’s DNA and with it the
coded instructions for making
proteins and other important
molecules.
Contains DNA (chromosomes or
chromatin)
Function:
Where RNA is made
Nuclear envelope
Function:
Controls what enters and exits the nucleus
Prokaryote or Eukaryote
eukaryotes
Plant or Animal
both
Nucleolus
Function:
Produces ribosomes
Inside the nucleus
Prokaryote or eukaryote:
eukaryote
Plant or animal:
both
Ribosomes
One of the most
important jobs
carried out in the cell
is making proteins.
Proteins are
assembled on
ribosomes.
Ribosomes are small
particles of RNA and
protein found
throughout the
cytoplasm.
Function:
Assemble amino acids to make proteins
Small and circular
Prokaryote or eukaryote:
both
Plant or animal:
both
Endoplasmic Reticulum
There are two types of ER –
rough and smooth
Rough endoplasmic reticulum:
Function:
“intracellular highway” used for transportation
Also produces proteins
Prokaryote or Eukaryote:
eukaryote
Plant or Animal:
both
Smooth endoplasmic reticulum:
Function
- “intracellular highway” used for transportation
- synthesizes membrane proteins
- detoxifies drugs
Prokaryote or eukaryote:
eukaryote
Plant or animal:
both
Golgi Apparatus
The Golgi apparatus appears as a stack of closely apposed
membranes
Function
Modifies, sorts and packages proteins and lipids to leave the cell
Flattened sacs
Prokaryote or Eukaryote
Eukaryote
Plant or Animal
Both
Lysosomes
Function:
- digests particles, such as food
- sacs of enzymes
Prokaryote or eukaryote:
eukaryote
Plant or animal:
animal
Vacuoles
In many plant cells there is a single, large
central vacuole filled with liquid.
Vacuoles are also found in some
unicellular organisms and in some
animals.
The paramecium contains a contractile
vacuole that pumps excess water out of
the cell.
Function:
Stores water, food,
enzymes and waste
Prokaryote or
Eukaryote:
Eukaryote
Plant or Animal:
both
Mitochondria
Nearly all eukaryotic cells contain mitochondria
Mitochondria convert the chemical energy
stored in food into compounds that are more
convenient for the cell to use.
Function:
- Makes energy
- The more mitochondria, the more energy the cell can produce
Chloroplasts
Plants and some other organisms contain chloroplasts
Chloroplasts capture energy from sunlight and convert it into chemical energy in a process called photosynthesis
Function:
Converts sunlight to usable
energy
Contains chlorophyll (green)
Prokaryotes or Eukaryotes:
Eukaryotes
Plant or Animals:
plants
