Review 1 Flashcards
What is an element
Each element is designated by its chemical
symbol (such as H, N, O, C, and Na), and
possesses unique properties.
-he number for each element is the atomic
number referring to the number of protons in
the nuclei of atoms
- Elements are comprised of atoms
What is an atom
Atoms are made of protons and neutrons located
within the nucleus, and electrons surrounding the
nucleus
* Atomic number (number of protons) for each
element is different
An atom is the smallest component of an
element that retains all of the chemical
properties of that element.
What is a macromolecule
Many critical nutrients come as
macromolecules
* macromolecules are built from different
combinations of smaller organic molecules
what is water
Water is cohesive: molecules form strong
bonds with each other
* Life’s most important molecule, and necessary
for life
* Small traces of it on another planet can indicate
that life could or did exist on that planet
* one of the most abundant molecules in living
cells
* Approximately 60–70% of your body is water
what is a biological macromolecule
large molecules
needed for life that are built from smaller
molecules
* Four major classes of biological macromolecules:
carbohydrates, lipids, proteins, and nucleic acids
* each is an important component of the cell and
performs a wide array of functions
* Combined, these molecules make up the majority
of a cell’s mass
What is carbon
Carbon can form:
* large branching chains with
other C
* Rings with other C
* Bonds with other elements (e.g.
N, O), which in turn form chains
and rings
what are the four classes of biological macromolectules
- Carbohydrates
- Lipids
- Proteins
- Nucleic Acids
- All made using carbon combined with other
elements
what are the types of carbohydrates
glucose
* Starch
* Glycogen
* Cellulose
* Chitin
what is glucose
glucose is the source of energy for cells
what is starch
Starch is the stored form of sugars in plants, and
is broken down into glucose
what is glycogen
Glycogen is the stored form of sugars in animals,
and is released into the bloodstream when
glucose levels are low
what is cellulose
Cellulose comprises the cell walls of plants, and
adds structural support to the cells
what is chitin
Chitin forms the exoskeleton of insects and crabs,
which works to protect their internal body parts
what is lipid
A group of compounds that do not dissolve in
water – they are non-polar
* provide insulation from the environment for
plants and animals
* E.g. help keep ducks dry because resist water
Cells store energy for long-term use as fats
* building blocks of many hormones
* an important part of the plasma membrane in
cells
what is protein
- abundant macromolecules with diverse functions
- E.g. animo acids
- Each cell in a living system may contain
thousands of different proteins, each with a
unique function. - Functions:
- Transport, storage, membranes, or structure for
living things
what are the types of proteins
enzymes and hormones
what is enzymes
produced by living cells, are catalysts
in biochemical reactions (like digestion) and
break down molecular bonds
* E.g. salivary amylase breaks down starch
what is hormones
chemical signaling molecules that act
to control specific physiological processes, like
growth, development, metabolism, and
reproduction.
* E.g. insulin is a protein hormone that maintains
blood glucose levels
what is amino acids
Are the macromolecule
building blocks that make up
all proteins
* There are 20 different animo
acids, and their structure in
one area of the molecule is
the only difference
* E.g. valine
what is nucleic acids
Macromolecules that carry the genetic
blueprint of a cell
* carry instructions for the functioning of the
cell
* Two main types: DNA and RNA
what is DNA
deoxyribonucleic acid (DNA)
* DNA is the genetic material found in all living
organisms, ranging from single-celled bacteria
to multicellular mammals.
* DNA molecules never leave the nucleus, but
instead use an RNA intermediary to
communicate with the rest of the cell
what is RNA
ribonucleic acid (RNA)
* mostly involved in protein synthesis
* Sent by DNA to communicate with the rest of
the cell
* involved in protein synthesis and its regulation
what is the cell
The smallest unit of a living thing
* The building blocks of all organisms
* In multicellular organisms, cells of the same
kind connect together
* They perform shared functions to form tissues
e.g. muscle tissue
* several tissues combine to form an organ (e.g.
brain)
what is the meaning of eukaryotic
animal, plant, fungal, protist cells
what is the meaning of prokaryotic
some bacteria and archaea cells
what is the unified cell theory
1) all living things are composed of one or
more cells
* 2) the cell is the basic unit of life
* 3) all new cells arise from existing cells
what are the characteristics of all cells
- All cells share four common components:
- 1) a plasma membrane (outer covering that
separates the cell’s interior from the surrounding
environment - 2) cytoplasm (a jelly-like region within the cell
where other cellular components are found) - 3) DNA (genetic material of the cell)
- 4) ribosomes (particles that make proteins)
what is the cytoplasm:
jelly-like substance that makes up
the contents of a cell between the plasma
membrane and nucleus
what is the cytoskeleton?
a network of protein
fibers in a cell’s cytoplams that helps
to maintain the shape of the cell
what is the flagella
long, hair-like
structures that extend from the plasma
membrane and are used to move a cell
what is cilia
short, hair-like
structures used to move cells or substances
along the outer cell membrane
what is ribosomes
enzyme complexes in the cell
responsible for protein synthesis.
what is the nucleus
the cell’s “brain”
what is chromosomes
structures within the nucleus
that are made up of DNA (hereditary material)
and proteins.
what is chromatin
DNA and proteins when not
distinguishable as chromosomes
what is the nucleolus
the part of the nucleus that directs
the synthesis of ribosomes
what is the endplasmic reticulum
On the outside of nucleus
* Membrane of ER is
continuous with nuclear
envelope
* a series of interconnected
membranous tubules that
modify proteins and
synthesize lipids
Rough ER: has ribosomes attached
Smooth ER: has few/no ribosomes on surface
* Is continuous with RER and part of nuclear
envelope
what is the golgi body
Sorts, tags, and distributes lipids and proteins
* A series of flattened membranous sacs in
cytoplasm
* Vesicles containing proteins/lipids that bud
from the ER go to golgi bodies
* Before reaching their final destination, the
lipids or proteins within the transport vesicles
need to be sorted, packaged, and tagged so
that they wind up in the right place
Tag proteins/lipids by adding a short chain of
sugar molecules that allow them to be routed
to proper destination in cell
* Usually many golgi bodies in cell, although
cells that secrete many molecules (e.g.
digestive cells that secrete enzymes) have
more than others
what is lysosomes
The “garbage disposal” in animal cells
* Contain digestive enzymes that aid the
breakdown of proteins, polysaccharides,
lipids, nucleic acids, worn-out organelles, and
disease-causing organisms
* In single-celled eukaryotes, lysosomes help
with food digestion and organelle recycling
Lysosome enzymes are active at a much lower
pH (more acidic) than those located in the
cytoplasm
* Many reactions that take place in the
cytoplasm could not occur at a low pH, thus
the advantage of compartmentalizing the
eukaryotic cell into organelles is apparen
what is phagocytosis
a section of the plasma membrane
folds in and engulfs a pathogen
what is vesticles and vacuoles
Vesicles and vacuoles are membrane-bound
sacs that function in storage and transport.
* Vacuoles: larger than vesicles; membrane
does not fuse with the membranes of other
cellular components
* Plant vacuole enzymes can break down
macromolecules
* Vesicles: smaller; membrane can fuse with
other membranes within the cell
what is the mitochondrial
powerhouses” of cell
* responsible for making adenosine triphosphate
(ATP), the cell’s main energy carrying molecule
* The formation of ATP from the breakdown of
glucose is known as cellular respiration
* Mitochondria are oval-shaped, double-membrane
organelles in cytoplasm
* Each membrane is phospholipid bilayer embedded
with proteins
* Also have their own ribosomes and DNA
* Muscles cells have many mitochonria, because need
lots of energy to contract
