BIO 131- Exam 1

Basic Features of a Cell (4)

- prokaryotic + eukaryotic

-plasma membrane

- fluid substance called cytosol

-chromosomes (carry genes)

-ribosomes (make proteins)

Where is most of the DNA in a eukaryotic cell?

nucleus: an organelle that is bounded by a double membrane.

What domains are prokaryotic cells in?

Bacteria + Archaea

Do Prokaryotic cells have a nucleus?

No Nucleus

Where is DNA in a prokaryotic cell?

- Nucleoid

- not enclosed by a membrane

Do prokaryotic cells have membrane-bound organelles?

No

What cells contain cytoplasm?

Prokaryotic + Eukaryotic

Both types of cells contain cytoplasm bound by the plasma membrane.

What does a prokaryotic cell look like?

typical rod shaped

Prokaryotic Cell Contains:

nucleoid, ribosomes, plasma membrane, cell wall, glycocalyx, flagella, fimbriae

What is Fimbriae?

attachment structures on the surface of some prokaryotes

What is a Nucleoid?

Region of prokaryotic cells where DNA is located

NOT enclosed by a membrane

What are Ribosomes?

complexes that synthesize proteins

What is the Plasma Membrane?

-a selective barrier that allows passage of oxygen, nutrients, and waste to service the volume of every cell.

-membrane enclosing the cytoplasm

What is the Cell Wall?

-rigid structure outside the plasma membrane

-ONLY IN PLANT CELLS

What is Glycocalyx?

the outer coating of many prokaryotes

consists of a capsule or a slime layer

Are eukaryotic or prokaryotic cells larger?

eukaryotic cells are larger

What is the membrane enclosing the cytoplasm?

plasma membrane

The structure of a plasma membrane is?

- double layer of phospholipids

- Hydrophilic heads with hydrophobic fatty acid tails

What do ribosomes use the information from DNA to make?

proteins

Nuclear Envelope

-encloses the nucleus, separating it from the cytoplasm.

Nuclear Envelope Structure

-double membrane

-each membrane consists of a lipid bilayer

The shape of the nucleus is maintained by... and is composed of...

the nuclear lamina ; protein filaments

What is DNA organized into?

chromosomes

What is a chromosome?

one long DNA molecule associated with proteins.

DNA + proteins of chromosomes together are called...

chromatin

nucleolus

located within the nucleus and is the site of ribosomal synthesis (rRNA)

What are ribosomes?

-carry out protein synthesis

-complexes of ribosomal RNA + protein

Where do ribosomes carry out protein synthesis? (2 places)

(1) in the cytosol (free ribosomes)

(2) on the outside of the ER or the nuclear envelope (bound ribosomes)

The 6 components of the endomembrane system are...

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

How are the parts of the endomembrane system connected?

through physical contact or by transport vesicles

What makes up more than half of the total membrane structure in cells?

endoplasmic reticulum

ER

network of membranous sacs and tubes; active in membrane synthesis and other synthetic and metabolic processes; has smooth + rough region

What does the smooth ER lack?

ribosomes

What are the smooth ER's primary functions? (4)

(1) synthesis of lipids

(2) metabolism of carbohydrates

(3) detoxification of drugs and poisons.

(4) stores calcium ions

What do the rough ER's bound ribosomes secrete?

-glycoproteins (proteins covalently bonded to carbohydrates)

What does the Golgi apparatus consist of?

- cisternae

- They are membrane-bound sacs that are stacked on top of one another

What are the functions of the golgi apparatus? (3)

POSTAL SYSTEM

proteins from the transport versicles are modified, stored, and shipped.

Specific:

-modifies products of the ER

-manufactures certain macromolecules

-sorts + packages materials into transport vesicles

What is a lysosome?

a membranous sac of hydrolytic enzymes that can digest macromolecules

Where do lysosomal enzymes work best?

acidic environment inside the lysosome

What is phagocytosis?

when some types of cells engulf another cell.

What is autophagy?

when lysosomes use enzymes to recycle the cell's own organelles and macromolecules.

What forms food vacuoles?

phagocytosis

• which is when specialized white blood vesicles eat and digest large particles such as bacteria, viruses, and dead tissue

What are vacuoles?

vacuoles are large vesicles derived from the endoplasmic reticulum and golgi apparatus.

What are contractile vacuoles?

pump excess water out of cells

What are central vacuoles?

PLANT CELLS
- a fluid filled storage organelle

- helps maintain cell shape and rigidity

- Fluid inside is made up of water, enzymes, and dissolved molecules

What are emergent properties?

characteristic that the system has but the individual parts don’t

emergent properties example w/ bike

a functioning bike emerging (working) only when the parts of it are put together in the correct way.

What are the levels of biological organization from smallest to largest? (9)

molecule - organelle - cell-tissue - organ - organism - population - community - ecosystem - biosphere

What are molecules?

-two or more atoms joined together

-they have individual characterisitics

organelle

-specialized structure that performs important cellular functions within a eukaryotic cell

-bunch of molecules put together

cell

-the basic unit of structure and function in living things

-put organelles together to make a cell and it has a lot more functioning than individuals organelles do

tissues

-group of cells that are joined in some way, working towards the same function

-tissue can protect and secrete

What is an organ?

-more than one tissue type working together

-organ system: all organs in a system working together to perform the same function.

organism

put all organ systems together to make this.

population

-all of the organisms of the same type/species in one location.

-ex: all of the students together in philly.

ecosystem

all of the communities and nonliving components interacting with each other.

biosphere

- all ecosystems together

- largest in order

At each level of the biological hierarchy we find a correlation between...

structure + function

A eukaryotic cell contains...

membrane-enclosed organelles and a DNA containing nucleus.

Prokaryotic cells lack...

a nucleus or other membrane bound organelles.

What are genes?

the units of inheritance that transmit information from parent to offspring.

Human body cells have how many chromosomes?

46 chromosomes ; 23 pairs

What is a DNA molecule made of?

two long strands arranged in a double helix

What is the universal genetic language common to all organisms?

DNA

What are the DNA nucleotides?

Adenine, Thymine, Cytosine, Guanine

What does DNA provide the blueprint for?

Making proteins.

What is gene expression?

converting information from a gene to its cellular product

[transcription, translation]

Nucleotides consist of...

-sugar molecule

-DNA: deoxyribose

-RNA: ribose

-thats attached to a phosphate group

-which is attached to one of the four nitrogen containing bases

Proteins do what for a cell?

-they can be regulatory, or provide structure, they can also provide signals that help cells communicate w/ each other.

Does gene expression need to be tightly regulated?

YES!!!!!!

Will every cell in you body express a gene?

-NO

-ex: a cell inside of your eyeball won't waste time or energy, making enzymes that digest milk because your eyeballs don't need to digest milk. They will spend time making enzymes SPECIFIC to the eye.

What makes life possible?

the sun and being able to transform one type of energy into other

How do producers make energy?

- Photosynthesis

-the chemical energy of these producers is then passed to consumers that feed on other organisms or their remains.

What flows through an ecosystem?

-energy

-generally entering as light and exiting as heat

What happens to chemical elements in an ecosystem?

they are recycled.

energy.... matter.... (Movement)

energy flows, matter cycles

What is evolution?

a process of biological change in which organisms gradually accumulate differences from their ancestors.

How do you explain similar traits in a two species?

descent from a common ancestor

evolution formal

change in the frequency of alleles in a given population over time.

A population is the smallest unit that can evolve a ____________ cannot.

individual

What is an allele?

-two or more different forms of the same gene

- like eye color or hair color

What are the three domains that biologists divide the kingdoms of life into?

bacteria, archaea, eukarya

What two domains are more closely related?

archaea and eukarya

What is in the domain eukarya?

-eukaryotes

-multicellular-plants, animals, fungi

What is in the domain bacteria + archaea?

-prokaryotes

-no nucleus

-very small

Charles Darwin Published?

"On the Origin of Species" (1859)

What two points did Darwin make?

(1) species showed evidence of "descent w/ modification" from common ancestors

(2) natural selection is the primary cause of descent w/ modification

Darwin observed that...

-individuals in a population vary in their traits, many of which are heritable

-more offspring are produced that survive, and competition is inevitable, and species generally suit their environment

Darwin reasoned that...

-individuals that are best suited to their environment are more likely to survive and reproduce

-over many generations, more individuals in a population will have the advantageous traits

Living organisms are made up fo chemical compounds based mostly on the element ________.

carbon (organic compound)

Molecules of all living things fall into what four main categories?

carbohydrates, lipids, proteins, nucleic acids

What can molecules can form macromolecules?

carbohydrates, lipids, proteins

dehydration reaction

-synthesizing a polymer

-create polymers from monomers

-two monomers are joined by removing one molecule fo water.

- a molecule of water is released w/ each covalent bond that is formed

What is a hydrolysis reaction

- CONSUMING WATER
- breaking down large molecules into smaller parts

What do carbohydrates include?

simple sugars and the polymers of sugar

What are the simplest carbohydrates?

monosaccharides or simple sugars

What are some simple sugars?

glucose, fructose, galactose

What is a polymer made from simple sugars?

starch

What are carbohydrate macromolecules?

- large biological molecule made of carbon, hydrogen, and oxygen atoms

- typically in a 1:2:1 ration

- Primary source for energy and provides structural support in living organisms

What are monosaccharides?

the monomers of carbohydrates