Lecture 1 - Cells Flashcards
To classify something as alive, scientists have come up with 8 characteristics, what are they?
ORGSHARE: order, reproduction, growth and development, sensitivity, homeostasis, adaptation, regulation, and energy processing
One of these is not like the others: ladybug, ebola virus, prickly pear cactus, and e.coli bacteria, and why?
ebola virus is different because it is not a living organism
Define the 8 characteristics of life!
Order: must be organized and made up of cells
Reproduction: must be able to pass hereditary information to the next generation
Growth and Development: grow and develop
Sensitivity: must respond to stimuli
Homeostasis: must be able to maintain constant internal conditions
Adaptation: must be able to enhance ability to survive and reproduce
Regulation: must be able to control internal functions
Energy processing: must be able to take energy from the sun or food to use for their metabolic activities
Do viruses satisfy the properties of life? why or why not?
NO!
Order: not made up of cells
Reproduction: they do reproduce but only inside other organisms
Growth and development: NO
Sensitivity: no metabolism to make energy to respond to stimuli
Homeostasis: NO
Adaptation: Yes they can change their DNA and RNA structure
Regulation: NO
Energy processing: NO
What are viruses made up of if not cells?
nucleic acid + protein coat/envelope
What are the levels of biological organization?
atom, molecule, organelle, cell, tissue, organ, organ system, organism, population, community, ecosystem, biome, biosphere
Describe atoms.
atoms are the smallest unit of matter: contains a nucleus surrounded by electrons. Example: hydrogen and oxygen
Describe molecules.
cluster of at least 2 atoms held together by chemical bonds. Example: H2O. 4 classes of macromolecules: nucleic acids, protein, carbohydrates, lipids
Describe the 4 classes of macromolecules.
1) Nucleic acids DNA/RNA: polymers of nucleotides ( nitrogenous base + sugar + phosphate )
2) Protein: polymers of amino acids
3) Carbohydrates: polymers of sugars
4) Lipids: includes triglycerides, phospholipids, and steroids
Are lipids polymers of anything?
No
Describe organelles.
membrane bound subcellular structure that performs a specific function within a cell. Example: mitochondria or golgi
Describe cells.
the smallest unit that displays all the characteristics of life. Some organisms are single cellular and some are multicellular. Cells are prokaryotic or eukaryotic. Example: stem cell and osteoblast
Describe tissues.
groups of similar cells carrying out a main function. 4 major tissue types: connective, epithelial, muscle, and nervous
What tissue is blood?
connective tissue
Describe organs.
collection of tissues that together perform a specific function. Example: stomach, intestine, heart
Describe organ system.
several organs that work together to perform a specific function. Example: digestive system
Describe organism.
an individual living thing. can be composed of many cells, tissues, organs, and organ systems working together or can be a single cell. Example: one elephant, one tree
Describe population.
all the individuals of a species living within a specific area. Example: all of the african bush elephants living in the savanna
Describe community.
all the living organisms of all the different species interacting in one area. Example: all the plants, animals, fungi, and microbes in the savanna
Describe ecosystem.
all the living and non living parts of a particular area. Eg: the savanna
What is biotic and abiotic
biotic: all the plants, animals, fungi, and microbes
abiotic: 4 abiotic conditions required for all living systems: water, gas, temperature, and nutrients/energy
Describe biomes.
major ecosystem types: characterized by specific climate/physical conditions and the organisms adapted to those conditions. Example: desert, tundra, broadleaf forest
Describe biosphere.
highest level of organization, all life and environments supporting life on earth. Example: land, water, atmosphere
Who proposed the cell theory?
Theodore Schwann
What is the cell theory?
1) all organisms are made up of cells
2) cells are the basic unit of life
3) all cells arise from preexisting cells
What is a unicellular organism?
all functions need to be carried out by the one cell. Example: bacteria, protists, and yeast
What is a multicellular organism?
many specialized cells that are dependant upon eachother for organism function and survival Example: human cells develop into specialized cells early in life
What are colonial organisms?
colony is made up of individual unicellular organisms that are physically connected
What is the main difference of a colonial organism vs a multicellular organism?
if separated from the colony, individual cell can survive on its own but this is not the case with multicellular organisms
What are the 3 domains of life?
bacteria, archaea, and eukarya
Bacteria and archaea are prokaryotic or eukaryotic?
prokaryotic cells
animals plants fungi and protists are prokaryotic or eukaryotic?
eukaryotic cells
what do all cells have in common
1) plasma membrane
2) cytoplasm
3) DNA
4) Ribosomes
Prokaryotic cells vs eukaryotic cells: compartmentalization?
prokaryotic: no compartmentalization meaning no membrane bound organelles and eukaryotic: compartmentalized meaning there are membrane bound organelles
Prokaryotic cells vs eukaryotic cells: nucleus
prokaryotic: no nucleus and the dna is within nucleoid
eukaryotic: has a nucleus and the dna is within nuclear membrane
Prokaryotic cells vs eukaryotic cells: circular vs linear dna
prokaryotic: dna is circular
eukaryotic: dna is linear
Prokaryotic cells vs eukaryotic cells: size
prokaryotic: smaller 1-5 um
eukaryotic: larger 10-100 um
Prokaryotic cells vs eukaryotic cells: unicellular vs colonial vs multicellular
prokaryotic: unicellular and colonial
eukaryotic: unicellular, colonial, multicellular
Prokaryotic cells vs eukaryotic cells: cell wall
prokaryotic: all have a cell wall
eukaryotic: some have cell wall and some only have membrane
what are some eukaryotic cell structures present in only animal cells?
lysosome, centriole, flagellum
what are some eukaryotic cell structures present in only
cell wall, chloroplast, central vacuole
what is the structure and function of the plasma membrane?
structure: phospholipid bilayer with proteins embedded.
function: surrounds cells to separate internal and external environment and regulates the passage of substrates.
IT IS SEMI PERMEABLE
Whats a phospholipid?
composed of 2 fatty acid chains, a glycerol backbone, and a phosphate group
what is the structure and function of cytoplasm?
structure: made of gel like cytosol
function: holds all the contents of a cell between the plasma membrane and the
nuclear envelope, such as organelles
what is the structure and function of the nucleus?
structure: surrounded by a double membrane called the nuclear envelope and stores the nuclear DNA in chromosomes
function: protects dna and controls all cell activities;information from dna is used to make rna and proteins
what is the structure and function of endoplasmic reticulum?
structure: network of flattened, interconnected membrane sacs; surrounds and is continuous with the nuclear envelope. It is divided into rough and smooth ER.
function: rough er function is protein synthesis, membrane synthesis and transports vesicles containing proteins to golgi apparatus
function: smooth er function is lipid synthesis, carbohydrate synthesis, detoxifies drugs, and stores calcium.
what is the structure and function of ribosomes?
structure: made of ribosomal rna and protein and dont have a membrane
function: carry out protein synthesis in 2 places 1) on the rough er and 2) in the cytosol
what is the structure and function of golgi?
structure: a stack of flattened membranous
stacks called cisternae
function: sorting, tagging, packaging, and
distribution of lipids and proteins ALSO Receives and modifies molecules made in the ER, packages them in vesicles and
directs them to locations within or for
export from cell
what is the structure and function of mitochondria?
structure: oval shaped double membrane organelles
inner layer: folds called cristae and have their own ribosomes and dna
function: cellular respiration: form atp by breaking down glucose: powerhouse of the cell
what is the structure and function of lysosomes?
structure: membranous sacs (single membrane)
containing hydrolytic enzymes
function: break down waste products : destroy/recycle molecules , organelles, and macromolecules: basically the cells garbage disposal
what is the structure and function of cell wall?
structure: rigid covering outside the plasma membrane made mostly of cellulose: in plants also in fungi and protists
function: provides support, protection, shape to cell and prevents excess water uptake
what is the structure and function of central vacuole?
structure: large water filled vacuole: takes up majority of the plant cell
function: regulates cell water levels: also stores cell wastes, toxins, nutrients, organic compounds
what is the structure and function of chloroplasts?
structure: have their own dna and ribosomes, have inner and outer membranes, inside has interconnected and stacked membrane sacs called thylakoids
function: for photosynthesis: green pigment called chlorophyll, which captures the energy of sunlight for photosynthesis
autotrophs vs heterotrophs?
plants: autotrophs: can make their own food
animals: heterotrophs: rely on other organisms for food
what is photosynthesis?
photosynthesis: light energy used to transform co2 and water into glucose and oxygen: this occurs in chloroplast
what is cellular respiration?
glucose is broken down to release energy in the form of atp: releases co2 and water by products: this occurs in mitochondria
