Traffic - Week 1 Flashcards
mechanistic approach
explains how - you shiver bc of a drop in body T
teleological approach
the why - shiver because you need to keep warm
Chemical Levels of Organization
atoms, molecules and cells - basic unit of living things.
All Cells…
obtain nutrients and O2, make energy, eliminate waste, make molecules, respond to change, exchange material, transport molecules, reproduce
Types of tissue
MENC - muscle, epithelial, nervous, connective
Types of muscle tissue
Skeletal, cardiac, smooth
Types of epithelial tissue
sheets and secretory glands
Nervous tissue is in the…
brain, spinal cord and nerves
Level of Organization (big picture)
cells, tissue, organs, organ systems, whole organism
Homeostasis
a dynamic equilibrium where body conditions are
maintained within narrow limits.
all cells are in contact with the aqueous (watery)
internal environment
homeostasis
extracellular fluid (ECF)
(1) plasma (fluid in the blood)
2) interstitial fluid (surrounding cells
Homeostasis maintains…
concentration of molecules, O2 and CO2, waste products, pH, water, salt levels, temp, volume and pressure
Sensor
a. monitors variable
b. responds to changes (stimuli) by sending input to integrator
integrator
determines set point (appropriate level of variable) b. compares set point to input c. sends response to effector
Effector
responds to changes
- most control systems operate using negative
feedback 1. decreases or shuts off original stimulus
2. resists change
Control mechanisms
sensor, integrator, effector
3 subdivisions of cells
plasma membrane, nucleus, cytoplasm
plasma membrane (cell membrane)
a.defines inside/outside
b. intracellular fluid (ICF) - inside cell c. extracellular fluid (ECF) - outside cell
d.selectively permeable - controls movement of
molecules between ICF and ECF
nucleus
a.usually near cell center
b. double layered membrane
c.contains DNA, “genetic blueprint,” directs protein
synthesis, control center of cell
cytoplasm
a. area between nucleus and plasma membrane
b. contains organelles
(1) separation of chemical reactions (2) specialized for a particular function
c. semiliquid, site of chemical reactions
- endoplasmic reticulum (ER)
interconnected fluid-filled membrane
Types of ER
a. smooth - interconnected tubules
b. rough - interconnected flattened sacs
(1) has ribosomes which help in protein synthesis (cell also has “free” ribosomes)
Rough ER
synthesizes proteins and lipids, releases them to ER
lumen. some will become new membrane for the cell or its organelles. Modified in lumen.
Smooth ER
in most cells it packages and transports products of rough ER (sections pinch off and become transport vesicles, move to Golgi complex)
Specialized Smooth ER
) lipid synthesis (steroid hormone secreting cells)
2) detoxify harmful substances (liver cells
(3) store calcium (muscle cells)
Golgi complex
layers of flattened membranous sacs (cisternae). processes ER products into final form
3. sorts and sends products to appropriate place. (secretion, exocytosis)
lysosomes
membrane containing hydrolytic enzymes. Digests bacteria. (1) pinocytosis - fluids, “cell drinking” (2) phagocytosis - large particles, “cell eating”
- peroxisomes
membrane sacs containing oxidative enzymes. use oxygen to remove hydrogen from molecules. Detoxifies - like alcohol.
mitochondria
have double membrane
a. inner membrane has folds called cristae b. matrix is gel inside.
apoptosis ( cell death)
3. converts energy from food into ATP (adenosine triphosphate)
three steps in forming ATP
glycolysis, citric acid cycle, electron transport chain
glycolysis
in cytosol (2) glucose ➝ 2 pyruvic acid (3) 2 ATP/glucose (4) attach H to carrier molecules making nadh this is anaerobic
citric acid cycle
needs oxygen (3) occurs in mitochondria acetyl CoA enters citric acid cycle (4) CO2 is produced (5) H attached to carrier molecules (NAD+, nicotinamide adenine dinucleotide; FAD, flavine adenine dinucleotide; become NADH and FADH2. 2 more ATP
electron transport chain/oxidative phosphorylation
needs oxygen. inner mitochondrial membrane that has electrons. NADH and FADH2 enter. electron removed from each H, ends up on O2. Energy from E used to transport H across inner membrane, this creates gradient. H+ can only flow back across channels with ATP synthase (chemiosmotic mechanism). Yields 28 ATP. O2 and H become H2O.
vaults
non-membranous, octagonal organelle made of
protein. used to transport molecules, mRNA. may help make cancer cells drug resistant.
Cytosol
(liquid part of the cytoplasm) 55% of cell volume. enzyme regulation of intermediary metabolism (means Molecules made and broken down). ribosome synthesis. storage of fat and glycogen.
Inclusion - masses of stored nutrients. No membrane. Can break down to make atp. provides raw material for structure
Cytoskeleton
TICS
protein network in cytosol
1. supports and organizes enzymes - rigidity
2. controls movements of cell and within cell
3. transport and movement
4. influence gene regulation
3 parts of Cytoskeleton
Microtubules, microfilaments, intermediate filaments
Cytoskeleton - Microtubules
largest, maintain shape in cell development (helpful in asymmetrical cells) transports vesicles (motor protein) , movement of cilia and flagella, form mitotic spindle. Made mostly of protein tubulin. Early in develop.
centrioles
part of cytoskeleton - organelle, no membrane. (a pair of microtubule groups)
assemble the mitotic spindle
Cytoskeleton - microfilaments
smaller, many made of actin, ring that divides a cell - pinches and separates halves
(3) amoeboid movement - some cells can break down actin filaments in order to move the whole cell (e.g., white blood. support microvilli. support microvilli - extensions of cytoplasm important for increasing surface area of cell
Cytoskeleton - intermediate filaments
medium size, made of different proteins, very stable. strengthen and stabilize cell, hold together contractile units in muscle cells. Made of hair and nails-keratin. Communication.
2 types of glands
Exocrine - secrete through ducts to outside of body
Endocrine - secrete hormones internally through blood
Microvilli
Help Increase surface area
Pseudopods
False feet
cilia
shorter, hairlike, many on a single cell; move substances across surface of cell (respiratory tract, oviduct)
flagella
long, one per human cell; move whole cell (sperm)
cilia and flagella on microtubule
both have same basic structure of grouped
microtubules; movement is produced when a motor protein (dynein) displaces tubules relative to one another
formation of mitotic spindle
(1) formed during mitosis (division of nucleus)
and directs movement of chromosomes (DNA)
(2) centrioles (a pair of microtubule groups)
assemble the mitotic spindle
cilia and flagella
both have same basic structure of grouped
microtubules; movement is produced when a motor protein (dynein) displaces tubules relative to one another
elements of cytoskeleton are interconnected
STOC
a. supports cell, responsible for rigidity and shape
b. organizes groups of enzymes
c. directs transport and movement
d. may transfer mechanical forces for communication, may influence gene regulation
body controlled
mainly by nervous and endocrine systems
size of human cell
10-20 μm in diameter
exocytosis
A secretory vesicle fuses with the plasma membrane, becomes part of the plasma membrane.
endocytosis
plasma membrane that pockets inward and pinches off as an endocytic vesicle. pseudopods.
in the citric acid cycle…
the building blocks of fats and proteins can be used to make ATP - they can be made into intermediate molecules
