Transcript Cell Structure and Function

Chapter 6-10
AP Biology
• Please take a moment to complete the KWL sheet that
you picked up as you came in.
• When you finish, complete the pre-lab questions for
the lab that we will do later today.
• Anton van Leeuwenhoek- first to view and describe
single-celled organisms, “animalcules”
• Robert Hooke- coined the term “cells.”
• Types of Microscopes
• Light Microscope- used to study living cells.
• Scanning Electron Microscope- used for study of the
topography (surface) of a specimen.
• Transmission Electron Microscope- used to study the internal
structure of cells.
• Cell Fractionation- a technique used for studying
cells- takes cells apart and separates major organelles
from one another.
• All living things are made of cells.
• Cells are the basic unit of structure and function in
living things.
• All cells come from pre-existing cells.
• Eukaryotic cells contain DNA in the nucleus.
Prokaryotic cells contain DNA in a concentrated region
called the nucleoid.
• Plasma Membrane- a
selective barrier
(semipermeable) that
allows passage of enough
oxygen, nutrients, and
wastes to and from the
cell.
• The plasma membrane is a
lipid bilayer embedded
with diverse proteins.
• As you ___________ the cell size, you ____________
the surface area to volume ratio, which ___________
the efficiency of transport across the cell membrane.
• Name the three main types of microscopes and
what they are used for.
• What does cell theory say?
• Where is the DNA stored in a prokaryote?
• Nucleus- contains cellular DNA
which includes most of the genes
in the cell. The nucleus is
surrounded by the nuclear
envelope.
• The nuclear envelope is a double
membrane made of 2 lipid
bilayers. Includes pore structures
that help regulate things entering
and exiting the nucleus.
• Nuclear Lamina- a net of protein
filaments that maintain shape of
nucleus and support nuclear
envelope.
• Chromosomes- structures that
carry genetic information (DNA).
Each chromosome contains one
long DNA molecule.
• Each eukaryotic species has a
distinct number of
chromosomes.
• Chromatin- the complex of DNA
and protein making up
chromosomes.
• Nucleolus- helps synthesize rRNA
(ribosomal RNA) and ribosomes.
• Ribosomes- made of rRNA and proteins- carry out
protein synthesis.
• Ribosomes exist as either free ribosomes (suspended in
cytosol) or bound ribosomes (attached to the Rough ER or
nuclear envelope)
• Endoplasmic Reticulum- consists of membranous
tubules, and sacs, called cisternae.
• Smooth ER- lacks ribosomes. Functions lipid synthesis,
detoxification, and storing calcium ions.
• Rough ER- has ribosomes on surface. Continuous with
the nuclear envelope. Synthesizes glycoproteins and
other secretory proteins.
• Golgi Apparatus- made of flattened membranous
sacs called cisternae. Has 2 sides the cis face
(receiving) and the trans face (shipping).
• Lysosome- contains hydrolytic enzymes used to digest
molecules.
• Phagocytosis- “cell eating”- lysosome digesting food
• Autophagy- lysosome breaking down damaged organelles.
• Vacuole- functions vary depending on cell type.
• Food Vacuole
• Contractile Vacuole
• Central Vacuole
• Mitochondria- site of cellular
respiration.
• Cellular Respiration- the process
that uses O2 to generate ATP by
extracting energy from sugars,
fats, and other fuels.
• Chloroplast- found in plants and algae- the site of
photosynthesis. Contain the green pigment chlorophyll.
• Is a member of the plastid family- a group of plant
organelles.
• Peroxisomes- contain enzymes that remove hydrogen
atoms and transfer them to oxygen, producing
hydrogen peroxide (H2O2).
• Describe the protein’s path through the cell, starting
with the mRNA molecule that specifies the protein.
• What sets the limit on how big or how small a cell is?
• Cytoskeleton- a network of fibers extending
throughout the cytoplasm- plays a major role in
organizing the structure and activities of the cells.
• Motor Proteins- allows for cell movement.
• Microtubules- the thickest cytoskeletal fiber, provide
a track that organelles with motor proteins can move
along. Help separate chromosomes during mitosis.
Form flagella and cilia.
• Centrosome- region where microtubules are organized.
Contains a pair of centrioles. Only in animal cells.
• Microfilaments- the thinnest fiber. Actin and myosin
filaments help muscle cells contract. Aide in
pseudopodia movement by converting cytoplasm from
a liquid to a gel.
• Cytoplasmic Streaming- circular flow of cytoplasm within
cells. Speeds distribution of cell materials.
• Intermediate Filaments- more permanent fixtures, fix
the position of organelles and shape of the cell.
Include keratin proteins.
• Cell Wall- extracellular structure of plant cells. Protects the
cell, maintains its shape, and prevents excessive uptake of
water. Holds the plant up against gravity.
• Primary Cell Wall, Middle Lamella, Secondary Cell Wall
• Plasmodesmata-perforations in the plant cell wall that allows
cytoplasm to be continuous between neighboring plant cells.
• Extracellular Matrix (ECM)- glycoproteins, carbohydrates and
proteoglycans that form strong fibers outside of cells.
• Tight Junctions- forms a seal around the cell by pulling
neighboring cells close together.
• Desmosomes- fasten cells together in strong sheets.
• Gap Junctions- form channels from one cell to adjacent cell.