cell structure and function Flashcards
the study of cells
cytology
the smallest living unit
cell
a living thing made of one cell
unicellular
a living thing made of many cells
multicellular
the 3-part idea that living things are made of cells, cells are the functioning units of living organisms, and cells come from the division of cells
cell theory
What had to be invented before the cell theory was developed?
microscope
How has the expansion of the cell theory been linked to technology?
As microscopes improve, we see more and understand cells better.
What type of microscope sees living organisms? Describe these microscopes.
compound light microscope - 2 lenses (curved glass) at opposite ends of a tube
What type of microscope sees more detail than light microscopes?
electron microscope
What are the two types of electron microscopes, and how are they different?
- SEM - scanning electron microscope - sees 3D images of cell surface
- TEM - transmission electron microscpe - sees slices of interior of cell
What are some advantages and disadvantages of electron microscopes?
advantages - works with a computer, can be color-enhanced, and see more detail
disadvantages - objects must be dead, actual image is black and white
Who named the cell while looking at cork? What is cork?
Robert Hooke - dead plant cells (cell walls)
Who invented an early microscope, saw living cells, and wrote journal entries?
Anton van Leeuwenhoek
Who studied plants and found that all plants are made of cells?
Matthias Schleiden
Who studied animals and found that all animals are made of cells
Theodor Schwann
Who was a physician who found that cells come from the division of pre-existing cells?
Rudolf Virchow
Who stained the cell and saw the nucleus?
Robert Brown
Who discovered the Golgi bodies
Camillo Golgi
Who came up with the idea of endosymbiosis?
Lynn Margulis
What important cell structure is a selectively permeable lipid bi-layer with embedded proteins that regulates the transport of materials in and out of a cell
cell membrane
What membrane chemical has a hydrophilic head and a hydrophobic tail and won’t let water through?
phospholipid
water loving
hydrophilic
water fearing
hydrophobic
this describes the cell membrane because it is in pieces of lipids, proteins, and carbs and can change
fluid mosaic
viscous living material inside a cell, everything between the cell membrane and nucleus
cytoplasm
the control center of a cell, contains DNA and RNA (genetic code), only found in eukaryotes surrounded by a membrane with nuclear pores
nucleus
What is the purpose of proteins in the cell membrane?
- channels
- carriers
- ID tags for white blood cells
- connections for tissues
What do we call cells with no nucleus or membrane-bound organelles?
prokaryotes
What are the only organisms that are prokaryotes?
bacteria
What do we call cells that do have a nucleus and membrane-bound organelles?
eukaryotes
What organisms have eukaryotic cells?
plants, animals, protists, and fungi
How are prokaryote chromosomes different from eukaryotic chromosomes?
prokaryotes - circular DNA
eukaryotes - linear DNA
any cell part
organelle
large storage structures that store water, salts, proteins, and carbs
vacuoles
a vacuole that can pump out excess water
contractile vacuole
smaller storage structures that move stuff around inside a cell or dump stuff out
vesicle
a digestive sac that contains hydrolytic enzymes, break down food and worn out organelles
lysosomes
framework of microfilaments and microtubules, causes cytoplasmic streaming
cytoskeleton
the protein threads of the cytoskeleton, made of tubulin (hollow)
microtubules
the protein threads of the cytoskeleton, made of actin (solid)
microfilaments
microtubule structures that organize the cytoskeleton during cell division (mitosis) - organize the mitotic spindle
centrioles
microtubule extensions on the cell surface that sweep materials along or help a cell move (paramecium)
cilia
microtubule extensions on the cell surface that help increase the surface area for absorption and secretion
microvilli
two-part RNA structure made in the nucleolus that makes proteins (2 types - free and fixed)
ribosomes
transport membranes to move lipids and proteins, connected to the nuclear envelope
endoplasmic reticulum
What is the difference between rough and smooth ER?
rough has ribosomes, and smooth does not
a stack of membranes that process and package chemicals into vesicles
Golgi apparatus
What is the central dogma of biology?
DNA codes for RNA which builds proteins
organelle where photosynthesis occurs
chloroplast
organelle where respiration occurs
mitochondrion
idea that eukaryotes came from prokaryotes living inside other prokaryotes
endosymbiosis
What makes the chloroplasts and mitochondria like bacteria?
- same size and shape
- have their own circular DNA
- have ribosomes
- reproduce themselves like binary fission
a rigid but porous structure outside the cell membrane of some cells
cell wall
What are cell walls of plants made of?
cellulose
What are cell walls of fungi made of?
chitin
What are cell walls of some bacteria made of?
peptidoglycan
the movement of materials through a cell membrane to allow the cell to get food, oxygen, water… and get rid of wastes
cell transport
What type of cell transport uses energy to move material from areas of low concentration to areas of high concentration
active transport
Name the three types of active transport.
- endocytosis
- exocytosis
- ion pumps (sodium-potassium pump)
What type of cell transport moves material from high to low concentration and doesn’t require energy?
passive transport
Name the three types of passive transport.
- diffusion
- osmosis
- facilitated diffusion
active transport where material is brought in through a membrane and pinched off into a vacuole
endocytosis
active transport where material is released through a cell membrane
exocytosis
endocytosis of solids - the way white blood cells consume germs
phagocytosis
active transport with special carrier proteins that use energy
ion pump
passive transport that moves any material from high to low concentration
diffusion
the diffusion of water
osmosis
diffusion through channel protein
facilitated diffusion
a region of high concentration
hypertonic
a region of low concentration
hypotonic
when two regions have equal concentration
isotonic
a difference in concentration from one area to another
concentration gradient
the force that causes water to flow toward higher solute concentration
osmotic pressure
water pushing against the inside of a plant cell making it firm
turgor pressure
special water channels for osmosis
aquaporins
Which way does water move when a cell is placed in a hypertonic environment?
water moves out and cell shrivels
Which way does water move when a cell is placed in a hypotonic environment?
water moves in and the cell swells (animal cells burst)
Why don’t plant cells burst?
cell wall prevents it
Why do hospitals use dextran or saline instead of pure water to rehydrate someone?
isotonic with body cells
when cells of multicellular organisms get specific jobs or functions (2 terms)
cell specialization
cell differentiation
Give some examples of specialized cells and what they do.
- red blood cells carry oxygen
- white blood cells fight infection
- nerve cells send messages
- muscle cells contract to move
a group of cells that work together
tissue - muscle, connective, nerve, epithelium
a group of tissues that work together
organ - heart, kidney, lung
a group of organs that work together
organ system - cardiovascular, digestive
energy stored in the bonds of compounds
chemical energy
stored chemical energy consumed by organisms as fuel
food
the energy value of food, raises temperature of 1 gram of water by 1 degree Celsius
calorie
1000 calories
1 Calorie (1 kilocalorie)
usable cell energy
ATP - adenosine triphosphate
What chemicals make up ATP?
adenosine, ribose, and 3 phosphates
partially used cell energy
ADP - adenosine diphosphate
What chemicals make up ADP?
adenosine, ribose and 2 phosphates
anaerobic respiration in yeast and other microbes, used in making beer and bread
alcoholic fermentation
anaerobic respiration in human muscles
lactic acid fermentation
the waste made by human muscles during anaerobic respiration - What does it do to the muscles?
lactic acid - causes fatigue
respiration with air (oxygen)
aerobic
respiration without air (oxygen)
anaerobic
a chemical that quickly replaces a phosphate on ADP to make ATP
creatine phosphate
Where is the energy stored in ATP, and how is it released?
in phosphate bonds - break off a phosphate
Which major type of respiration makes more energy and less waste?
aerobic
Where does aerobic respiration occur?
Where does anaerobic respiration occur?
aerobic - mitochondrion
anaerobic - cytoplasm
What is the problem with aerobic respiration?
slower
What are the waste products of aerobic respiration, and what happens to them?
CO2 and H2O - exhaled
a color
pigment
the green pigment in plants that traps sunlight
chlorophyll
organelle where photosynthesis occurs
chloroplasts
all the wavelengths of energy from the sun
electromagnetic spectrum
the part of the electromagnetic spectrum we can see, ROY G BIV
visible light
What is produced by photosynthesis?
carbohydrates (sugar (glucose) and starch) and oxygen
Where do plants get the needed energy for photosynthesis?
sunlight
What factors affect the rate of photosynthesis and how?
- light intensity - more light means more photosynthesis until it reaches the maximum rate
- availability of CO2 and H2O - more reactants mean more photosynthesis until it reaches the maximum rate
- temperature - enzymes work best between 0-35 degrees Celsius then change shape and quit working
What happens to the surface to volume ratio of a cell as it grows? How does this affect the cell?
As a cell grows, the ratio of surface to volume decreases making it harder for the cell to get needed materials and remove wastes.
What is the advantage of asexual reproduction? disadvantage?
faster - makes more copies in a stable environment
cells are identical - no diversity
What is the advantage of sexual reproduction? disadvantage?
slower, but produces diversity in a changing environment
DNA in a cell that is not dividing
chromatin
DNA in a cell that is dividing
chromosomes
1/2 of a replicated chromosome
sister chromatid
the structure that holds replicated sister chromatids together
centromere
the part of the cell cycle where a cell spends most of its time and is doing its regular metabolic activities
interphase
the part of the cell cycle where the cell is making daughter cells
cell division
the division of the nucleus
mitosis
the division of the cytoplasm
cytokinesis
Name the 3 parts of interphase, and say what happens in each step.
G1 - growth, doubles in size and does metabolic activity
S - DNA replicates
G2 - growth in preparation for mitosis
Name the 4 phases of mitosis in order, and say what happens in each step.
- prophase - chromosomes form
- metaphase - chromosomes line up at the equator
- anaphase - replicated chromosomes pull apart
- telophase - get two identical nuclei
What phase of mitosis is the longest?
prophase
What 2 phases of mitosis are opposites?
prophase and telophase
How is mitosis different in plants and animals?
- animals have centrioles - plants don’t
2. plants make a cell plate while animals cleave (pinch in)
a disease of uncontrolled cell division
cancer
a mass of cells
tumor
chemicals that cause cancer
carcinogens
