BIO 1114 - Ch 3 - Cells

Confocal light microscope

-enhances resolution by focusing light on one small area of the specimen. • Fluorescent dyes can be attached to specific cell structures which emit light when excited by a laser, making them easier to see -light is like a laser beam -can stain proteins/organelles to see what's happening in cell

SEM microscope

-scanning electron microscope also very powerful and reveals details on cell surfaces. • It bounces electrons off the surface of cells

cell membrane functions

1. Forms a barrier between the cell and the outside world 2. Regulates passage of substances in and out of the cell - helps maintain homeostasis

Microtubules

A hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells and is found in cilia and flagella.

central vacuole

A large vacuole that rests at the center of most plant cells and is filled with a solution that contains a high concentration of solutes Cellular digestion occurs in large central vacuoles, which also help regulate the size and water balance of plant cells

amphipathic

A molecule that has both a hydrophilic region and a hydrophobic region • Hydrophilic head: polar bonds, which are attracted to water • Hydrophobic tails: nonpolar bonds, which repel water

Phospholipids

A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail

Cytoskeleton

A network of long protein strands in the cytosol that helps support the cell found in eukaryotic cells

endomembrane system

A network of membranes inside and around a eukaryotic cell, related either through direct physical contact or by the transfer of membranous vesicles

Cell theory states

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

______________ processes take place inside cells to carry out the basic functions of life.

Biochemical

peroxisomes

Break down fatty acids and produce hydrogen peroxide aid in digestion They originate at the ER and contain enzymes that digest and then oxidize certain toxic molecules

prokaryotes

Cells that do not contain nuclei (bacteria and archaea) They are small, simple in structure and lack a nucleus Bacteria and archaea are two different domains of prokaryotes

eukaryotes

Cells that enclose their DNA in nuclei They are larger and more complex, with many internal parts including a nucleus and other membranous organelles

What specifies the "recipe" for proteins?

DNA

What does the nucleus contain?

DNA and nucleolus (RNA)

What are the 3 cell domains?

Domain bacteria domain archaea domain Eurkarya

nuclear envelope

Double membrane perforated with pores that control the flow of materials in and out of the nucleus

membrane proteins

Embedded proteins that perform specific functions for the cell membrane

active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

animal cells are ______________

Eukaryotic

plant cells are _______________

Eukaryotic

T or F: mitochondria are paternally inherited

F. they are maternally inherited

membrane steroids

Fit between the tails of fatty acids of the phospholipid molecules; makes the membrane less permeable and decreases its flexibility The membrane steroids keep the membrane at the right level of fluidity- not too soft, not too stiff

Thykaloid

Flattened sac of membrane on chloroplast that contains chlorophyll and other pigments that carry out photosynthesis

nucleolus

Found inside the nucleus and synthesizes/produces ribosomes

Proteins move from rER into the _________

Golgi

cristae

Infoldings of the inner membrane of a mitochondrion that houses the electron transport chain and the enzyme catalyzing the synthesis of ATP

matrix

Innermost compartment of the mitochondrion

plasma membrane (cell membrane)

It's function is to protect the cell and control what goes in and out. It is not a solid structure. It is made of millions of smaller molecules so it is flexible and porous (allows things to pass through it).

Microfilaments

Long, thin fibers that function in the movement and support of the cell

cell wall functions

Maintains shape of the bacterium regulate volume prevent cell from bursting when it takes in too much water almost all bacteria have one Helps protect cell from osmotic lysis Helps protect from toxic materials May contribute to pathogenicity

Ribosomes

Makes proteins Some ribosomes float in the cytosol; others attach to the rER.

Photosynthesis

Plants use the sun's energy to convert water and carbon dioxide into sugars

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

cellular respiration

Process in the mitochondria that releases energy by breaking down glucose and other food molecules in the presence of oxygen

cell diffusion

Process that causes molecules to move in or out of the cell It's how Oxygen gets in and CO2 gets out

Secreted proteins leave the cell

Proteins leaving golgi are sorted and packaged into new transport vesicles

Messenger RNA (mRNA)

RNA molecule that carries copies of instructions for the assembly of amino acids into proteins from DNA to the rest of the cell it matches the sequence of the DNA

Lysosomes contain hydrolytic enzymes

Some transport vesicles leaving the Golgi carry enzymes that catalyze hydrolysis reactions These vesicles fuse with lysosomes, where cellular digestion of large molecules occurs

T or F: Cells vary greatly in size

T

T or F: Most cells are too small to be seen without a microscope

T

T or F: phospholipids are ampiphatic

T

cell

The basic unit of structure and function in living things the smallest unit of life

Stroma

The fluid of the chloroplast surrounding the thylakoid membrane; involved in the synthesis of organic molecules from carbon dioxide and water

intermediate filaments

Threadlike varied proteins in the cell's cytoskeleton that are roughly twice as thick as microfilaments

Golgi apparatus

a complex of vesicles and folded membranes within the cytoplasm of most eukaryotic cells, involved in secretion and intracellular transport Inside the Golgi, proteins are chemically modified to become functional

transport vesicles

a small membranous sac in a eukaryotic cell's cytoplasm carrying molecules produced by the cell

phospholipid bilayer

a two-layered arrangement of phosphate and lipid molecules that form a cell membrane, the hydrophobic lipid ends facing inward and the hydrophilic phosphate ends facing outward

protein secretion

active movement out of cell proteins tagged for secretion via signal sequence of amino acids The different parts of the endomembrane system work together to secrete proteins, moving them outside of the cell

protein localization

antibodies that bind to specific proteins can allow you to determine where a protein accumulates- comparing RNA and protein accumulation can reveal examples of post transcriptional regulation

Notice that _________ and _________ cells are about 10 times smaller in diameter than most plant and animal cells

bacteria; archaea

Eukaryotic cells divide the labor ______ _____________

cell membrane

lysosomes

cell organelle filled with enzymes needed to break down certain materials (food, worn out cell parts) in the cell

Different _____ _______ characterize life's three domains

cell types • Some features are common to all three domains (cell membrane). • Others are only found in one domain (nucleus). • Each domain has its own unique combination of features

DNA in prokaryotic cells

coiled into a region called the nucleoid, but no membrane surrounds the DNA

plant cell

contains a cell wall, chloroplast and large vacuole They have most of the same membrane-bounded organelles as animal cells but notice the large central vacuole, cell wall, and chloroplasts

Free floating ribosomes synthesize proteins that will function in the __________

cystol

animal cell

does not have a cell wall or chloroplast and a small vacuole They have many different membrane-bounded organelles

Select all the roles that membranes play in cells.

enclose organelles in eukaryotic cells receive and respond to external stimuli transport substances into and out of the cell transcribe DNA into RNA and assemble ribosomes Options 1-3

hydrolytic enzymes

enzymes that speed up/aid in the breakdown of chemical bonds through the addition of water (hydrolysis)

Protists, fungi, plants, and animals are ___________

eukaryotic

Almost all cells have thousands of mitochondria

eurkaryotic

What are 4 things cells have, regardless of size?

genetical material ribosomes cytoplasm cell membrane

A phospholipid is made of a molecule of __________, a ___________ _______, and two __________ _________

glycerol; phosphate group; fatty acids

The phosphate "head" end of a phospholipid is ______, meaning its polar covalent bonds attract water, but the tails of a phospholipid are ______ and thus face away from water.

hydrophilic; hydrophobic

The portion of the "tail" of a phospholipid bilayer is hydrophilic or hydrophobic?

hydrophobic

membrane carbohydrates

interact with the surface molecules of other cells, facilitating cell-cell recognition Chains of sugars are attached to some of the protein and phospholipids in cell membranes. • They play roles in cell-cell communication

Most plant cells lack __________

lysosomes

cellular digestion centers

lysosomes, vacuoles, peroxisomes

These are the sites for the chemical reactions of cellular respiration

matrix and cristae

A ___________ surrounds each cell

membrane

compound light microscope

microscope that allows light to pass through a specimen and uses two lenses to form an image

the endomembrane system consists of

nuclear envelope, endoplasmic reticulum, golgi apparatus, lysosomes, vacuoles and the plasma membrane

mRNA is transported out of nucleus through

nuclear pores

What controls protein production?

nucleus

Chloroplast

organelle found in cells of plants and some other organisms that captures the energy from sunlight and converts it into chemical energy Eukaryotes that carry out photosynthesis include plants and some protists

Ribosomes attached to the rER synthesize proteins that function inside of _____________ or outside of the _______

organelles; cell

Transport vesicles leave the Golgi and move to fuse with the _____ ___________, expelling the proteins to the __________ of the cell.

outside

nuclear pore

passageway for molecules into and out of the nucleus

What spontaneously form a bilayer when they are surrounded by water?

phospholipids

Bacteria are what cell type?

prokaryotes

What are the most ancient forms of life?

prokaryotes

After synthesis, proteins enter the ____

rER Proteins that will be secreted move from ribosomes into the rER, where they are modified and folded into their exact 3D shape The proteins travel out from the ER in bubbles of membrane called transport vesicles

RNA binds to a ______________ after leaving the _________

ribosome; nucleus

bacteria

single-celled organisms that lack a nucleus They lack membrane-bounded organelles. Their ribosomes and DNA are free in the cytoplasm

cholesterol is an example of a membrane ________

steroid

plant cell wall

strong, protective structure made from cellulose fibrils

TEM microscope

transmission electron microscope • A transmission electron microscope (TEM) is a very powerful tool for seeing internal cell structures. • It transmits electrons right through cells

interconnected components of a cytoskeleton

• Microfilaments • Intermediate filaments • Microtubules All three are connected to one another and function together, creating an intricate meshwork

features of a cell membrane

• Organelles involved in protein production • Organelles involved in protein localization • Organelles involved in cellular digestion • Energy-related organelles • The cytoskeleton • Structures outside cells

cytoskeleton function

• Structural support • Aids in cell division • Organelle transport • Cell movement

organelles in cytoplasm

• Structures with membranes that perform specific functions • Prokaryotes can perform most or all of these functions, though they lack membrane-bound organelles

Cell membranes separate the cell from its surroundings

• The membrane forms a seal that only lets certain substances in or out • A phospholipid bilayer is selectively permeable to lipids and small, nonpolar molecules

Why are cells so small?

• smaller cells have more surface area across which to pass oxygen, nutrients and waste materials • High surface area allows the cell to quickly exchange materials with its surroundings. • For example, oxygen from the air must quickly enter your lung cells.

membrane protein functions

* sites for hormone-binding * enzymatic action * cell adhesion * cell-to-cell communication * channels for passive transport * pumps for active transport • Transport proteins • Enzymes • Recognition proteins • Adhesion proteins • Receptor proteins

anatomy of a cell

- Cells are not all the same - All cells share general structures - All cells have three main regions - Nucleus - Cytoplasm - Plasma Membrane

Prokaryotes vs. Eukaryotes

- Prokaryotes have no nucleus or membrane bound organelles - Eukaryotes have a nucleus and membrane bound organelles - Both can reproduce and respond to the environment