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What types of macromolecules make up the cell membrane?
phospholipids, proteins, carbohydrates
What are the functions of proteins?
Control the rate of reactions, Regulate cell processes, used to form bones and muscles, transport substances into and out of the cell, help fight diseases.
What are the functions of carbohydrates?
energy source (glucose in respiration)
energy store (starch in plants, glycogen in animals)
structure (cellulose in cell wall of plants)
What are the functions of phospholipids?
Allow lipid-soluble substances to enter and leave cell
Prevent water-soluble substances entering and leaving cell
Make membrane flexible and self-sealing
What is the function of peripheral proteins?
they are confined to the inner and outer surface
act as receptors for hormones or neurotransmitters (cell recognition)
they can dissociate from the membrane and move into cytoplasm
What is the function of integral proteins?
Binds to hydrophobic centers and functions as channels, receptors, carriers, enzymes and pumps
What is the function of glycoproteins?
Used as cell membrane markers to identify cells as "Self" or "Non-self".
What is the function of receptor proteins?
detect signals and transmit them to the cell's response machinery
What is the function of recognition proteins?
provide a "fingerprint" for the cell, so it can be recognized by other cells
What is the function of enzymatic proteins?
accelerate chemical reactions
What is the function of transport proteins?
transport of substances
What are the characteristics of passive transport?
Passive transport requires no energy. Particles are moving down their concentration gradient. Passive transport may be regular diffusion or osmosis. It may use proteins in facilitated diffusion.
What is transported in osmosis?
water
How is water transported in osmosis?
transported through a semi-permeable membrane
What is transported in regular diffusion?
molecules and ions
How does regular diffusion work?
The molecules move from a region of higher concentration to a region of lower concentration until the concentration becomes equal throughout
What are the characteristics of active transport?
Active transport requires energy as molecules move against their concentration gradient. ATP is the energy source for active transport.
How does primary active transport work?
relies directly on the hydrolysis of ATP
How does secondary active transport work?
It takes advantage of a gradient that has already provided energy.
How does endocytosis work?
A large molecule is taken into the membrane by being enclosed in a vesicle.
How does exocytosis work?
Large molecules within cells are packaged into secretory vesicles, which then fuse with the plasma membrane and release their contents into the extracellular fluid.
Hypertonic environment
-an environment in which there is more solute outside the cell than inside the cell
-water leaves the cell and the cell shrinks
-animal cells will eventually die, but plant cells will plasmolysize
Hypotonic environment
-an environment in which there is less solute outside the cell than inside the cell
-water enters the cell, causing the cell to puff up and burst
-animal cells will burst, while plant cells will only become rigid because of its cell wall
Isotonic environment
-The concentration of a solution is the same inside and outside the cell
-water stays the same
-cell stays the same
What are the two reasons why cells divide rather than continuing growth?
The larger a cell becomes, the more demands the cell places on its DNA. In addition, the cell has more trouble moving enough nutrients and wastes across the membrane.
Where is the genetic information stored?
in the DNA, which is in the Nucleus.
What is the name for DNA structure?
double helix
Gene
A segment of DNA on a chromosome that codes for a specific trait
What are specific requirements a cell needs?
food, water and oxygen
Cell division
Process by which a cell divides into two new daughter cells
Are the daughter cells identical or different from the mother cell?
identical
What must happen prior to cell division?
DNA must be replicated
What is the size of the daughter cell compared to the parent cell initially?
Half the size of the mother, the cell eventually grows to normal size
How many chromosomes do humans have?
46 (23 pairs)
What are the two stages of cell division?
mitosis and cytokinesis
What holds the duplicated chromosomes together?
centromere
What is the cell cycle?
series of events that cells go through as they grow and divide
What phases make up interphase?
G1, S, G2
What happens during G1?
Cell growth
What happens during S?
DNA replication
What happens during G2?
cell growth and preparation for division
Which is the longest phase of the cell cycle?
G1
What happens for the cell to prepare for division?
the cell grows, replicates its DNA, and prepares to divide.
What is PMAT?
prophase, metaphase, anaphase, telophase
What happens during metaphase, anaphase and telophase of Mitosis?
During metaphase, sister chromatids align along the middle of the cell by attaching their centromeres to the spindle fibers. During anaphase, sister chromatids physically separate at the centromere and pull towards opposite poles of the cell by the mitotic spindle. During telophase, the cell fully divides.
What is cytokinesis?
division of the cytoplasm
What are the results of mitosis in unicellular vs multicellular organisms?
In unicellular organisms, the cell is directly divided into two parts. This type of cell division is called amitosis. In case of multicellular organisms. karyokinesis (division of nucleus) takes place before the division of cytoplasm.
Do all cells go through replication at the same rate?
No, not all cells divide at the same rate
What are the "controls" of cell division?
Hormones.
Mitogens.
Size of the cell.
Growing factors.
Physical signals.
Chemical signals.
Ratio of Karyoplasmic.
Why are there "checkpoints" in the cell cycle?
to prevent the cell from progressing to the next phase of the cell cycle before the prior phase has been completed.
What is the G0 phase?
If the cell does not receive the go ahead for G1, it goes to G0 where it does not replicate.
Cancer
any malignant growth or tumor caused by abnormal and uncontrolled cell division
What is the purpose of photosynthesis?
to make glucose
Why is it essential that photosynthesis occur for organisms outside of the plant kingdom?
provides energy for most life on earth.
What is the simplified equation for photosynthesis?
6CO2 + 6H2O = C6H12O6 + 6O2
What are the benefits of xylem and phloem?
Xylem transports and stores water and water-soluble nutrients in vascular plants. Phloem is responsible for transporting sugars, proteins, and other organic molecules in plants.
Where does photosynthesis occur?
Chloroplast
Chlorophyll
A green pigment found in the chloroplasts of plants, algae, and some bacteria
What is the role of leaves?
Leaves capture the sun's energy and carry out the food-making process of photosynthesis.
Chloroplast structure
contains a plant cell's thylakoids, stroma and grana, and chlorophyll
What happens in the thylakoid vs the stroma?
Thylakoid - light-dependent reactions
Stroma - light-independent reactions
What are the factors that affect the rate of photosynthesis?
light intensity, carbon dioxide concentration, and temperature
What are the reactants and products of light dependent reactions?
NADP, ADP, and water molecules
What are the 2 reactions in photosynthesis?
light-dependent reactions, which take place in the thylakoids, and light-independent reactions (also known as dark reactions or the Calvin cycle),
What is the purpose of the light independent reaction?
To make glucose
Which stage are the reactants used in photosynthesis?
light-dependent reactions
Which stage are the products produced in photosynthesis?
The Calvin Cycle
What does O2 benefit?
stored for energy and released as a byproduct.
The light independent reaction is the first time what molecule shows up?
CO2
What is the Calvin Cycle? What is the purpose of the Calvin Cycle?
The cycle that uses chemical energy to store chemical energy as sugars and incoporate CO2; to turn carbon dioxide from the air into sugar, the food autotrophs need to grow.
What is the end product of the Calvin Cycle?
glucose
Which groups of living organisms carry out cellular respiration?
Plants, animals, fungi, protists, and bacteria
What is the purpose of cellular respiration?
to make energy, or ATP, for the cell
What is the simplified equation for respiration?
C6H12O6 + 6O2 → 6CO2 + 6H2O
Where does cellular respiration take place?
mitochondria
What are the 3 stages of cellular respiration?
glycolysis, krebs cycle, electron transport chain
What type of macromolecule are DNA and RNA?
nucleic acids
What is the monomer of a nucleic acid?
nucleotide
What is the purpose of DNA?
store genetic information
How would you differentiate between DNA and RNA?
DNA is double-stranded, forming a double helix, while RNA is usually single-stranded. The sugar in DNA is deoxyribose, whereas RNA contains ribose. DNA uses the base thymine, while RNA uses uracil.
What are the 3 parts of a nucleotide?
sugar, phosphate, nitrogen base
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