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what the sigma

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